TY - CONF A1 - Reinsch, Stefan A1 - Böcker, Wolfgang D. G. A1 - Bücker, Michael A1 - Seeger, Stefan A1 - Unger, Brita ED - Specht, K. T1 - Development of wood-inorganic composites with enhanced properties and environmental stability T2 - 4th International Wood and Natural Fibre Composites Symposium CY - Kassel, Germany DA - 2002-04-10 PY - 2002 VL - 4 SP - 50-1-50-6 CY - Kassel AN - OPUS4-1365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf A1 - Weh, Lothar A1 - Reinsch, Stefan T1 - Oberflächenprofile partiell kristallisierter Silikatgläser T2 - 73. Glastechnische Tagung CY - Halle (Saale), Deutschland DA - 1999-05-31 KW - Kristallisation KW - Silikatgläser PY - 1999 SP - 26 EP - 29 CY - Frankfurt/Main AN - OPUS4-819 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Chládek, Jirí A1 - Müller, Ralf A1 - Weh, Lothar T1 - Viskoses Fließen und Oberflächenkristallisation an Vickerseindrücken T2 - 76. Glastechnische Tagung CY - Bad Soden, Deutschland DA - 2002-05-27 PY - 2002 SP - 250 EP - 253 PB - DGG, Deutsche Glastechnische Gesellschaft e.V. CY - Frankfurt/M. AN - OPUS4-1872 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Chládek, Jirí A1 - Müller, Ralf A1 - Weh, Lothar A1 - Reinsch, Stefan T1 - Surface Crystallisation Patterns Caused by Vickers Indentation T2 - Proceedings of workshop 2002 ; 10th Annual University-wide Seminar Workshop 2002 CY - Prague, Czech Republic DA - 2002-02-11 PY - 2002 SN - 80-01-02511-X VL - 6A SP - 610 EP - 611 PB - Czech Technical University CY - Prague AN - OPUS4-1870 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bücker, Michael A1 - Böcker, Wolfgang D. G. A1 - Reinsch, Stefan A1 - Unger, Brita ED - Acker, J. V. T1 - Wood Modification by Sol-Gel Derived Precursors T2 - 1st European Conference on Wood Modification ; 1st ECWM 2003 CY - Ghent, Belgium DA - 2003-04-03 KW - Silica-sol treatment KW - Wood-inorganic composite KW - Water repellency KW - Environmental stability PY - 2003 SN - 90-806565-2-6 SN - 1018-5593 SP - 255 EP - 259 PB - Univ., Laboratory of Wood Technology CY - Ghent AN - OPUS4-2521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Kristallwachstumsgeschwindigkeit und -mechanismen von mu-Cordierit zwischen 800 und 1350°C T2 - 77. Glastechnische Tagung CY - Leipzig, Deutschland DA - 2003-05-26 PY - 2003 VL - 77 SP - 1 EP - 4 PB - DGG CY - Offenbach AN - OPUS4-2526 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Böcker, Wolfgang D. G. A1 - Bücker, Michael A1 - Reinsch, Stefan A1 - Unger, Brita A1 - Britz, Roswitha T1 - Mineralisiertes Holz - Verbundwerkstoff mit verbesserten Eigenschaften PY - 2001 CY - München AN - OPUS4-1197 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Scholz, G. ED - Krämer, V. T1 - Phasentransformationen von anorganisch modifizierten Alumo-Xerogelen T2 - Jahrestagung der Gesellschaft für Thermische Analyse e.V. CY - Augsburg, Deutschland DA - 2003-09-15 PY - 2003 SP - 1 EP - 2 AN - OPUS4-2668 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bücker, Michael A1 - Böcker, Wolfgang D. G. A1 - Reinsch, Stefan A1 - Unger, Brita ED - Wielage, B. ED - Leonhardt, G. T1 - Entwicklung umweltverträglicher Holzverbundwerkstoffe mit verbesserter biologischer und Feuchtebeständigkeit T2 - Tagung "Verbundwerkstoffe und Werkstoffverbunde" CY - Chemnitz, Deutschland DA - 2001-09-05 PY - 2001 SN - 3-527-30319-7 SP - 463 EP - 467 PB - Wiley-VCH CY - Weinheim AN - OPUS4-1160 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böcker, Wolfgang D. G. A1 - Bücker, Michael A1 - Reinsch, Stefan A1 - Unger, Brita T1 - Holzverbundwerkstoffe mit verbesserten Eigenschaften N2 - Die offenporige Struktur des Holzes und dessen chemische Zusammensetzung bieten sich an, über Tränkverfahren geeignete Precursoren so an den inneren Oberflächen des Holzes zu fixieren, dass bei anschließender thermischer Behandlung ein umweltfreundlicher anorganisch-organischer Verbundwerkstoff entsteht. Aus der Literatur sind hierzu verschiedene Ansätze bekannt. - Ziel der vorliegenden Arbeit sind Verbesserungen der biologischen Beständigkeit, der Feuchtebeständigkeit unter Beibehaltung bzw. leichter Verbesserung der mechanischen Eigenschaften des Holzes. Dies wird durch eine chemische Verbindung (Haftung) zwischen den verbundbildenden Phasen Holz und Precursor und eventuell zusätzlichen Einbau von funktionellen organischen Gruppen realisiert. Als Precursoren dienen über den Sol-Gel Weg hergestellte Kieselsole, die nach vollständiger thermischer Umsetzung zu rein anorganischen Phasen (SiO2) führen. Die Sol-Gel Synthese konnte so optimiert werden, dass durch die Behandlung eine homogene Beschichtung aller Oberflächen erreicht werden kann. T2 - Integrierter Umweltschutz im Bereich der Holzwirtschaft CY - Göttingen, Deutschland DA - 2002-01-22 PY - 2002 SP - 100 EP - 102 PB - DGfH CY - München AN - OPUS4-1366 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Nascimento, M.L.F. A1 - Zanotto, E. D. T1 - Crystal Growth Mechanism in Cordierite and Diopside Glasses in Wide Temperature Ranges T2 - XX. International Congress on Glass CY - Kyoto, Japan DA - 2004-09-26 KW - Cordierite KW - Diopside KW - Glass KW - Crystal growth PY - 2004 SP - 6 pages PB - Ceramic Society of Japan CY - Tokio AN - OPUS4-4389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Eberstein, Markus A1 - Thiel, A. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Lösungs- und Kristallisationsvorgänge beim Sintern von Glasmatrix-Kompositen T2 - 79. Glastechnische Tagung CY - Würzburg, Deutschland DA - 2005-05-23 KW - Glaspulver KW - Glasmatrix-Komposit KW - Sintern KW - Kristallisation PY - 2005 SN - 3-921089-43-3 SP - 7 Seiten PB - Deutsche Glastechnische Gesellschaft CY - Offenbach AN - OPUS4-10377 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Schadrack, Reinhard A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Glastransformationstemperatur wasserhaltiger Gläser T2 - 80. Glastechnische Tagung CY - Dresden, Germany DA - 2006-06-12 PY - 2006 AN - OPUS4-12485 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Behrens, H. T1 - Mechanical loss spectroscopy on water enriched glasses T2 - 8. Internationales Otto-Schott-Kolloquium CY - Jena, Germany DA - 2006-07-23 PY - 2006 AN - OPUS4-12487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chladek, J. A1 - Müller, Ralf A1 - Weh, Lothar A1 - Reinsch, Stefan T1 - Viscous flow and surface crystallization caused by Vickers indentation PY - 2004 SN - 0927-4472 VL - 77 IS - 1 SP - 1 EP - 6 PB - Elsevier CY - Amsterdam AN - OPUS4-6235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmelzer, J.W.P. A1 - Potapov, O. V. A1 - Fokin, V. M. A1 - Müller, Ralf A1 - Reinsch, Stefan T1 - The effect of elastic stress and relaxation on crystal nucleation in lithium disilicate glass N2 - In the framework of a general theoretical approach recently developed, the effect of elastic stresses on the rate of nucleation of crystallites of critical sizes in the process of crystallization of lithium disilicate glasses is studied. Hereby both the evolution of elastic stresses – due to changes in the specific volume of the crystallizing system (i.e., differences in the densities of the melt and the crystal) – and their relaxation – connected with viscous flow – are taken into consideration. If the classical theory of nucleation is employed for the determination of the nucleation rates (modified by taking into account elastic stresses), elastic stresses may lead, for the system under consideration, to a decrease of the nucleation rate by up to two orders of magnitude. As shown, the theory allows an at least qualitatively correct incorporation of the effect of elastic stresses and stress relaxation into the description of nucleation phenomena in glass-forming melts. PY - 2004 U6 - https://doi.org/10.1016/j.jnoncrysol.2003.10.002 SN - 0022-3093 VL - 333 IS - 2 SP - 150 EP - 160 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-6236 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Böcker, Wolfgang D. G. A1 - Bücker, Michael A1 - Reinsch, Stefan A1 - Unger, Brita T1 - Abschlussbericht zum Vorhaben Verbundwerkstoff - Mineralisiertes Holz - FKZ: 033 9829 - Förderschwerpunkt "Integrierter Umweltschutz im Bereich der Holzwirtschaft" des Bundesministeriums für Bildung, Wissenschaft, Forschung und Technologie, BMBF - Projektlaufzeit: 1.10.2000-30.9.2003 KW - Mineralisiertes Holz KW - Sol-Gel KW - Holz KW - Vakuumtränkung KW - Holzschutz KW - Biozide PY - 2004 SP - 1 EP - 94 CY - Berlin AN - OPUS4-12055 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Thermomechanisches Verhalten wasserhaltiger Glasschmelzen - Herstellung von Gläsern mit mittleren Wassergehalten T2 - Workshop Wasser im Glas CY - Berlin, Germany DA - 2004-12-08 PY - 2004 AN - OPUS4-5733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Herstellung von Gläsern mittlerer Wassergehalte T2 - 79. Glastechnische Tagung CY - Würzburg, Deutschland DA - 2005-05-23 KW - Glas KW - Wassergehalt PY - 2005 SN - 3-921089-43-3 SP - 4 Seiten PB - Deutsche Glastechnische Gesellschaft CY - Offenbach AN - OPUS4-7606 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reinsch, Stefan A1 - Schadrack, Reinhard A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Bestimmung der Glastransformationstemperatur wasserhaltiger Gläser T2 - 80. Glastechnische Tagung CY - Dresden, Deutschland DA - 2006-06-12 PY - 2006 SN - 3-921089-46-8 SP - 1(?) EP - 5(?) PB - Verl. d. Dt. Glastechn. Ges. CY - Offenbach AN - OPUS4-12552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wondraczek, L. A1 - Reinsch, Stefan A1 - Gaber, Martin A1 - Deubener, J. A1 - Müller, Ralf A1 - Komatsu, T. T1 - Nano-crystalline germanate glass-ceramics T2 - 78. Glastechnische Tagung CY - Nürnberg, Deutschland DA - 2004-06-07 PY - 2004 SP - 37 EP - 40 PB - Deutsche Glastechnische Gesellschaft CY - Offenbach AN - OPUS4-6953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bücker, Michael A1 - Böcker, Wolfgang D. G. A1 - Reinsch, Stefan A1 - Unger, Brita T1 - Holzmodifikation durch Tränkung mit Nanopartikeln T2 - Tagung "Rosenheimer Fenstertage 2004" CY - Rosenheim, Deutschland DA - 2004-01-01 KW - Holzmodifikation KW - Sol-Gel KW - Tränkverfahren KW - Holzschutz PY - 2004 SP - 23 EP - 26 PB - Institut für Fenstertechnik CY - Rosenheim AN - OPUS4-4487 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Nascimento, M.L.F. A1 - Zanotto, E. D. T1 - Crystal Growth Mechanism in Cordierite and Diopside Glasses in wide Temperature Ranges T2 - XX. International Congress on Glass CY - Kyoto, Japan DA - 2004-09-26 PY - 2004 AN - OPUS4-5622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Scholz, G. T1 - Beziehungen zwischen Zusammensetzung und thermischen Eigenschaften von Alumo-Xerogelen T2 - Jahrestagung der Gesellschaft für thermische Analyse (GEFTA) CY - Braunschweig, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-5620 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nagamine, K. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Honma, T. A1 - Komatsu, T. T1 - Crystallization behavior of lithium iron phosphate glass powders in different atmospheres N2 - Crystallization behavior in different atmospheres (air, Ar, and 7% H2/Ar) of lithium iron phosphate glass (33Li2O–33Fe2O3–1Nb2O5–33P2O5 (LFNP)) powders with different sizes of 2–1000 µm was examined. The crystallization peak temperature (Tp) in Ar and 7% H2/Ar decreased with decreasing the particle size of glass powders, but the value of Tp in air was independent of particle size. The crystallized glass obtained by heating to Tp showed the formation of the α-Li3Fe2(PO4)3 and LiFePO4 crystalline phases. Fe2O3 crystals were formed only in the inside of crystallized glass plates in the heating in air. The crystallization of LiFePO4 was largely enhanced in the particle size of <2 µm during the heating in Ar and 7% H2/Ar atmospheres. The main crystallization mechanism in LFNP glass was found to be surface crystallization. Significant shrinkages were observed for glass compacts (pellets) in the heating in 7% H2/Ar. These results suggest that controlling particle sizes and atmospheres enables the design the morphology of LiFePO4 crystals in LFNP glass. KW - DTA KW - Kristallisation KW - Phasenentwicklung KW - Unterschiedliche Atmosphären KW - Lithiumionen-Batterie PY - 2011 U6 - https://doi.org/10.1111/j.1551-2916.2011.04579.x SN - 0002-7820 SN - 1551-2916 VL - 94 IS - 9 SP - 2890 EP - 2895 PB - Blackwell Publishing CY - Malden AN - OPUS4-24914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Erfurt, Darja A1 - Goedecke, Caroline T1 - Processing and sinter-crystallization of alkaline earth silicate glass powders T2 - 11th ESG Conference CY - Maastricht, Netherlands DA - 2012-06-03 PY - 2012 AN - OPUS4-27417 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dressler, M. A1 - Börnstein, Julian A1 - Meinel, M. A1 - Ploska, Ute A1 - Reinsch, Stefan A1 - Hodoroaba, Vasile-Dan A1 - Nicolaides, Dagmar A1 - Wenzel, Klaus-Jürgen T1 - Sol-gel preparation of calcium titanium phosphate: viscosity, thermal properties and solubility N2 - Calcium titanium phosphate (CTP) was prepared by the sol–gel route in order to prepare suitable coatings. This work addresses the question of how to prepare stable CTP sols. Their rheological properties as a function of process parameters like solid loading and water content are investigated. It was found that an increased solid loading as well as an increased water content lead to an increased initial viscosity as well as a more pronounced ageing induced viscosity rise. In addition, the thermal behavior of the resulting xerogels was analyzed. Furthermore, we studied the ion release behavior of the xerogels when brought in contact with water. Results suggest that calcium titanium phosphate shows a diffusion controlled ion release mode with a preferential release of Ca. KW - Calcium titanium phosphate KW - Sol-gel processing KW - Rheology KW - Thermal analysis KW - Coatings KW - Solubility PY - 2012 U6 - https://doi.org/10.1007/s10971-011-2653-y SN - 0928-0707 SN - 1573-4846 VL - 62 IS - 3 SP - 273 EP - 280 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-27617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Brita A1 - Bücker, Michael A1 - Reinsch, Stefan A1 - Hübert, Thomas T1 - Chemical aspects of wood modification by sol-gel-derived silica N2 - It has been shown that tetraethoxysilane-derived precursors are suitable solutions for impregnating pine sapwood to improve its dimensional stability. Tailored sol–gel syntheses result in precursors with nano-scaled silica species which are able to penetrate into the cell walls of wood. The physical fixation of those species inside the cell walls was verified by ESEM/EDX investigations. There is evidence that the silica species are chemically bonded to wood components. Nonreacted alkoxy groups can exist in the wood composites after impregnation. The amount of these organic residues depends on the composition of the precursors, especially their condensation degree and reactivity. Treatments for finishing the composites after the impregnation step to get clean products and stable properties are discussed in this context. An explanation of the complex relationship between solids content in the impregnation solutions and percentage weight gain and bulking of the composites is given. It can be demonstrated that high WPG values (>20 %) are pre-conditions for an effective protection of the resulting composites but they only guarantee efficient improvements if connected with the incorporation of the inorganic component inside the cell walls. Therefore, the sol–gel syntheses have to be carried out in such a manner that very small (<2 nm) as well as reactive species are sufficiently available. This demands syntheses using sub-stoichiometric water contents (H2O/TEOS <4, better <2). KW - Silica-wood composites KW - Sol-gel derived precursors KW - Curing KW - Fixation of silica KW - Dimensional stability PY - 2013 U6 - https://doi.org/10.1007/s00226-012-0486-7 SN - 0043-7719 SN - 1432-5225 VL - 47 IS - 1 SP - 83 EP - 104 PB - Springer CY - Berlin AN - OPUS4-26258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bücker, Michael A1 - Böcker, Wolfgang D. G. A1 - Reinsch, Stefan A1 - Unger, Brita T1 - Alternativer Holzschutz KW - Holzschutz KW - Kieselsol KW - Biozide KW - Sol-Gel-Prozess PY - 2004 SN - 1435-1854 IS - 11 SP - 77 EP - 80 PB - Verl. f. Fachpublizistik CY - Stuttgart AN - OPUS4-6333 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Herstellung von Gläsern mittlerer Wassergehalte T2 - 79. Glastechnische Tagung CY - Würzburg, Germany DA - 2005-05-23 PY - 2005 AN - OPUS4-7805 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberstein, Markus A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Rabe, Torsten A1 - Schiller, Wolfgang Arno A1 - Thiel, A. A1 - Deubener, J. T1 - Kinetic Modeling of LTCC-Shrinkage T2 - 3rd International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2007) CY - Denver, CO, USA DA - 2007-04-23 KW - LTCC KW - Glass matrix composites KW - Inclusions KW - Sintering kinetics KW - Modeling PY - 2007 SP - 1 EP - 8 PB - American Ceramic Soc. CY - Denver AN - OPUS4-14948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Schiller, Wolfgang Arno T1 - Rate controlled debindering of glass ceramic composites T2 - 9th ESG Conf. with the Annual Meeting of the ICG Glass - The challenge for the 21st century CY - Trencín, Slovakia DA - 2008-06-22 PY - 2008 AN - OPUS4-16687 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Kristallwachstumgeschwindigkeit und -mechanismen von m-Cordiert zwischen 800 und 1350°C T2 - 77. Glastechnische Tagung CY - Leipzig, Germany DA - 2003-05-26 PY - 2003 AN - OPUS4-4744 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Scholz, G. T1 - Phasentransformationen von anorganisch modifizierten Alumo-Xerogelen T2 - Jahrestagung der Gesellschaft für Thermische Analyse e.V. (GEFTA 2003) CY - Augsburg, Germany DA - 15.09.2003 PY - 2003 AN - OPUS4-4746 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Shi, Meng A1 - Eberstein, Markus A1 - Thiel, A. A1 - Müller, Ralf A1 - Deubener, J. T1 - Partial solution of dispersed alpha-Al2O3-particles in alumoborosilicate glass T2 - 81. GlastechnischeTagung und 4. DGG-Symposium "Novel Optical Technologies" CY - Aachen, Germany DA - 2007-06-04 PY - 2007 AN - OPUS4-15494 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Eberstein, Markus A1 - Thiel, A. A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Effect of dispersed Al2O2-particles on sintering of glass matrix composites T2 - 10th International Conference and Exhibition of the European Ceramic Society CY - Berlin, Germany DA - 2007-06-17 PY - 2007 AN - OPUS4-15495 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eberstein, Markus A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Rabe, Torsten A1 - Schiller, Wolfgang Arno A1 - Thiel, A. A1 - Deubener, J. T1 - Kinetic Modeling of LTCC Shrinkage: Effect of Alumina Content N2 - We studied sintering of LTCC-type glass matrix composites (GMCs) consisting of small glass and alumina particles of equal size. Primarily, crystals act as rigid inclusions, decelerating the densification rate. In later stages, they also dissolve, partially increasing the viscosity. Release of alumina finally induces crystallization of alumosilicates, which enables post-firing stability. To study both effects, two model GMCs were prepared: an α-Al2O3 + barium alumoborosilicate glass (BABS)–GMC, which shows neither significant dissolution nor crystallization, and an α-Al2O3 + calcium alumoborosilicate glass (CABS)–GMC, which dissolves readily and promotes crystallization. The kinetics of shrinkage for both GMC were modeled by utilizing Frenkel theory for the early stage and Mackenzie–Shuttleworth theory for the late stage, assuming that sintering is superimposed by the weighted contributions of triparticle glass–crystal clusters, their random occurrence (ideal mixing), and a shrinkage rate controlled by the GMC effective viscosity. In agreement with modeling, the experimental results showed that the shrinkage rate of BABS–GMC decreases progressively for crystal volume fractions Φ > 0.15. The attainable shrinkage is reduced by up to 8% for Φ = 0.45. For the CABS–GMC with Φ = 0.25, a reduction of Φ to 0.20 was evident due to partial α-Al2O3 dissolution. This effect was found able to increase the sintering temperature by ~50–60 K. KW - LTCC KW - Glas Matrix Composites KW - Inclusions KW - Sintering Kinetics KW - Modeling PY - 2007 SN - 1551-4897 VL - 4 IS - 4 SP - 173 EP - 180 CY - Washington, DC AN - OPUS4-16506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Eberstein, Markus A1 - Deubener, J. A1 - Thiel, A. A1 - Schiller, Wolfgang Arno ED - J.G. Heinrich, ED - C.G. Aneziris, T1 - Effect of dispersed Al2O3 particles on sintering of glass matrix composites T2 - 10th International Conference of the European Ceramic Society CY - Berlin DA - 2007-06-17 KW - LTCC KW - Glass matrix composites KW - Inclusions KW - Sintering kinetics KW - Modelling PY - 2007 SN - 3-87264-022-4 SP - 290 EP - 295 PB - Göller CY - Baden-Baden AN - OPUS4-17445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Eberstein, Markus A1 - Deubener, J. A1 - Thiel, A. A1 - Schiller, Wolfgang Arno T1 - Effects of dispersed Al2O3 particles on sintering of LTCC N2 - The sintering of Low Temperature Co-fired Ceramics prepared from alumoborosilicate glass- and Al2O3 powders of similar small particle size was studied by dilatometry, heating microscopy, microstructure analysis, glass- and effective viscosity measurements. The steric effect of Al3O3 inclusions was studied using a gnon-reactiveh model composite. With increasing Al3O3 volume fraction (Φ ≤ 0.45), sintering decelerates and its final stage shifts to higher temperature. The attainable shrinkage is reduced as Al2O3 particle clusters bearing residual pores become more frequent. The kinetics of sintering could be described formally superposing the weighed contributions of differentially sized and randomly composed glass-crystal particle clusters and assuming a sintering rate controlled by the effective matrix viscosity, which increases with Φ and with progressive wetting of Al2O3 particles during densification. The "reactive" model composite shows significant dissolution of Al2O3 into the glass, which has two opposed effects on sintering: reducing Φ and increasing glass viscosity. For the present case (Φ = 0.25), the latter effect dominates and sintering is retarded by Al2O3 dissolution. Crystallization of wollastonite starts after full densification. Dissolution of Al2O3 was found to promote the subsequent growth of anorthite. KW - LTCC KW - Glass matrix composites KW - Al2O3-inclusions KW - Sintering kinetics PY - 2005 SN - 1022-6680 SN - 1662-8985 VL - 39-40 SP - 375 EP - 380 PB - Trans Tech Publ. CY - Zurich AN - OPUS4-18441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Nascimento, M.L.F. A1 - Müller, Ralf A1 - Zanotto, E. D. T1 - Crystal growth kinetics in cordierite and diopside glasses in wide temperature ranges N2 - We measured and collected literature data for the crystal growth rate, u(T), of µ-cordierite (2MgO · 2Al2O3 · 5SiO2) and diopside (CaO · MgO · 2SiO2) in their isochemical glass forming melts. The data cover exceptionally wide temperature ranges, i.e. 800–1350 °C for cordierite and 750–1378 °C for diopside. The maximum of u(T) occurs at about 1250 °C for both systems. A smooth shoulder is observed around 970 °C for µ-cordierite. Based on measured and collected viscosity data, we fitted u(T) using standard crystal growth models. For diopside, the experimental u(T) fits well to the 2D surface nucleation model and also to the screw dislocation growth mechanism. However, the screw dislocation model yields parameters of more significant physical meaning. For cordierite, these two models also describe the experimental growth rates. However, the best fittings of u(T) including the observed shoulder, were attained for a combined mechanism, assuming that the melt/crystal interface growing from screw dislocations is additionally roughened by superimposed 2D surface nucleation at large undercoolings, starting at a temperature around the shoulder. The good fittings indicate that viscosity can be used to assess the transport mechanism that determines crystal growth in these two systems, from the melting point Tm down to about Tg, with no sign of a breakdown of the Stokes–Einstein/Eyring equation. KW - Crystal growth KW - Oxide glasses KW - Silicates KW - Kristallwachstumsgeschwindigkeit KW - Kinetik KW - Silikatgläser PY - 2008 U6 - https://doi.org/10.1016/j.jnoncrysol.2008.09.007 SN - 0022-3093 VL - 354 IS - 52-54 SP - 5386 EP - 5394 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dreßler, Martin A1 - Dörfel, Ilona A1 - Reinsch, Stefan A1 - Saliwan Neumann, Romeo T1 - Korundhaltige Aluminiumoxidschichten T2 - 15. Symposium: Verbundwerkstoffe und Werkstoffverbunde CY - Kassel, Germany DA - 2005-04-06 PY - 2005 UR - http://www.dgm.de/download/tg/706/706_85.pdf SP - 5 Seiten PB - DGM CY - Kassel AN - OPUS4-7522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Ralf A1 - Eberstein, Markus A1 - Reinsch, Stefan A1 - Schiller, Wolfgang Arno A1 - Deubener, J. A1 - Thiel, A. T1 - Effect of rigid inclusions on sintering of low temperature co-fired ceramics KW - Sintering KW - Glass Matrix Composites KW - Rigid Inclusion KW - Effective Viscosity KW - Kinetic Modelling KW - LTCC PY - 2007 SN - 1753-3562 SN - 0017-1050 SN - 0031-9090 SN - 1750-6697 VL - 48 IS - 4 SP - 259 EP - 266 PB - Society of Glass Technology CY - Sheffield AN - OPUS4-16211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Thiel, A. A1 - Eberstein, Markus A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Viskosität von sinternden Glas/Kristallphasen-Kompositen T2 - 80. Glastechnische Tagung CY - Dresden, Deutschland DA - 2006-06-12 PY - 2006 SN - 3-921089-46-8 SP - 1(?) EP - 3(?) PB - Verl. d. Dt. Glastechn. Ges. CY - Offenbach AN - OPUS4-14045 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Eberstein, Markus A1 - Thiel, A. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Sinterkinetik von Glasmatrix-Kompositen mit reaktiver Dispersphase T2 - 80. Glastechnische Tagung CY - Dresden, Deutschland DA - 2006-06-12 PY - 2006 SN - 3-921089-46-8 SP - 4 Seiten PB - Verl. d. Dt. Glastechn. Ges. CY - Offenbach AN - OPUS4-14046 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Malz, Frank A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Reinsch, Stefan A1 - Scholz, G. T1 - Aluminum speciation and thermal evolution of aluminas resulting from modified Yoldas sols N2 - Aluminas resulting from sols prepared via a modified Yoldas procedure were studied with differential thermal analysis (DTA), differential thermal gravimetrie (DTG), 27Al nuclear magnetic resonance (27Al MAS NMR) and X-ray diffraction (XRD) concerning their thermal properties, aluminum speciation and phase content. Hydrolysis of aluminum-sec-butoxide in aluminum nitrate solutions allowed to prepare stable sols with varying NO3-/Al molar ratios, solids contents and pH values. Resulting sols contained different aluminum species including also Al13 polycations. Sol preparation conditions also determined aluminum speciation in solid products obtained after thermal treatments of gels obtained from these sols. Al13 polycations and AlO5 species were found to play an important role for thermally induced transformation from amorphous products via eta-Al2O3 to alpha-Al2O3. Intermediately formed eta-Al2O3 promotes the phase transformation to alpha-Al2O3. KW - Alumina KW - Modified Yoldas sols KW - 27Al nuclear magnetic resonance KW - Differential thermal analysis KW - X-ray diffraction PY - 2007 U6 - https://doi.org/10.1016/j.jssc.2007.06.018 SN - 0022-4596 SN - 1095-726X VL - 180 IS - 9 SP - 2409 EP - 2419 PB - Elsevier CY - San Diego, Calif. AN - OPUS4-16189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reinsch, Stefan A1 - Meng, S. A1 - Eberstein, Markus A1 - Thiel, A. A1 - Müller, Ralf A1 - Deubener, J. T1 - Partial Solution of Dispersed alpha-Al2O3-Particles in Alumoborosilicate Glass T2 - 81. Glastechnische Tagung CY - Aachen, Deutschland DA - 2007-06-04 KW - Glasmatrixkomposite KW - Lösung KW - Sintern PY - 2007 SN - 978-3-921089-52-1 IS - CD-ROM SP - 1 EP - 5 PB - Deutsche Glastechnische Gesellschaft CY - Offenbach AN - OPUS4-16108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Eberstein, Markus A1 - Müller, Ralf A1 - Schiller, Wolfgang Arno A1 - Thiel, A. A1 - Deubener, J. T1 - Einflüsse mikrodisperser Al203-Einschlüsse auf die Sinterung von LTCC T2 - 82. Glastechn. Tagung CY - Hamelin, Germany DA - 2008-05-19 PY - 2008 AN - OPUS4-17648 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Gaber, Martin A1 - Müller, Ralf A1 - Schiller, Wolfgang Arno T1 - Rate controlled debindering of glass ceramic composites N2 - Green compacts of ceramics, glass ceramic composites and sinter glass ceramics contain different amounts of organic materials added as pressing aids or binders. Before sintering, these organics have to burn out completely. In oxidising atmospheres, the debindering process is mostly exothermic and therefore difficult to control. This uncontrolled heat production due to locally enhanced debindering and respective gas release may cause damages in the green compact microstructure. Therefore, debindering is usually operated with very low heating rates (< 3 K/min) which requires long processing times of many hours. In this paper, we will show that it is possible to reduce the processing time for debindering dramatically by using the decomposition rate of the organic binder, detected by the weight loss of the sample, as a control factor of the furnace. T2 - 9th ESG (European Society of Glass) Conference with the Annual Meeting of the ICG Glass - "The challenge for the 21st century" CY - Trencin, Slovakia DA - 2008-06-22 KW - Debindering KW - Thermo gravimetry KW - Glass ceramic composites PY - 2005 SN - 1022-6680 SN - 1662-8985 VL - 39-40 SP - 583 EP - 586 PB - Trans Tech Publ. CY - Zurich AN - OPUS4-17840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Eberstein, Markus A1 - Müller, Ralf A1 - Thiel, A. A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Sinterkinetik von Glasmatrix-Kompositen T2 - Symp. HLK 2008, Keramik in Wissenschaft und Praxis CY - Hamburg, Germany DA - 2008-02-26 PY - 2008 AN - OPUS4-18226 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Deubener, J. A1 - Behrens, H. A1 - Müller, Ralf A1 - Zietka, S. A1 - Reinsch, Stefan T1 - Kinetic fragility of hydrous soda-lime-silica glasses N2 - The effect of hydration on the kinetic fragility of soda-lime-silica glasses was investigated by viscometry in the glass transition range. Water-bearing glasses were prepared from industrial float glass (FG) and a ternary model glass (NCS = 16Na2O 10CaO 74SiO2 in mol%) by bubbling steam through the melt at 1480 °C and up to 7 bar. Additionally, a sodium borosilicate glass (NBS = 16Na2O 10B2O3 74SiO2 in mol%) was hydrated under equal conditions. As detected by infrared spectroscopy water dissolves in the glasses exclusively as OH-groups. The hydration resulted in a total water content CW up to ~ 0.2 wt% for FG, NCS and NBS glasses. Kinetic fragility, expressed by the steepness index m, was determined from the temperature dependence of η at the glass transition. Viscosity data from previous studies on hydrous float glasses (CW > 1 wt%) were surveyed together with literature data on the (H2O)–Na2O–CaO–SiO2, (H2O)–Na2O–SiO2 and (H2O)–SiO2 systems to expand the range of water concentration and bulk composition. We could demonstrate that m decreases for all glasses although water is dissolved as OH and should depolymerize the network. An empirical equation of the general type m = a - b logCW where a, b are fitting parameters, enables m to be predicted, for each glass series as function of the water content CW. The enlarged data base shows that the parameter B of the Arrhenius viscosity-temperature relation decreases much stronger than the isokom temperature at the glass transition. KW - Soda-lime-silica KW - Fragility KW - Viscosity KW - Water in glass PY - 2008 U6 - https://doi.org/10.1016/j.jnoncrysol.2008.04.021 SN - 0022-3093 VL - 354 IS - 42-44 SP - 4713 EP - 4718 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Schmidt, I. A1 - Müller, Ralf A1 - Kraft, T. A1 - Deubener, J. T1 - Sinterkinetik von Glasmatrixkompositen für Low temperature Co-fired Ceramics T2 - DKG-Jahrestagung 2009 CY - Aachen, Germany DA - 2009-03-23 PY - 2009 AN - OPUS4-19695 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. T1 - Dissolution of alumina in glass matrix composites T2 - Crystallization 2009, 9th Intern. Symp. on Crystallization in Glasses and Liquids CY - Curitiba, Brazil DA - 2009-09-10 PY - 2009 AN - OPUS4-20209 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Eberstein, Markus A1 - Deubener, J. T1 - Sintering kinetics of glass matrix composites for LTCC T2 - Crystallization 2009, 9th Intern. Symp. on Crystallization in Glasses and Liquids CY - Curitiba, Brazil DA - 2009-09-10 PY - 2009 AN - OPUS4-20210 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Rosemann, Maik A1 - Müller, Ralf A1 - Deubener, J. T1 - Crystallization of glass matrix composites for LTCC T2 - TC7-Meeting im Rahmen der Crystallization 2009, 9th Intern. Symp. on Crystallization in Glasses and Liquids CY - Curitiba, Brazil DA - 2009-09-10 PY - 2009 AN - OPUS4-20211 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Ralf A1 - Meszaros, Robert A1 - Peplinski, Burkhard A1 - Reinsch, Stefan A1 - Eberstein, Markus A1 - Schiller, Wolfgang Arno A1 - Deubener, J. T1 - Dissolution of alumina, sintering, and crystallization in glass ceramic composites for LTCC KW - LTCC KW - Sintering KW - Crystallization KW - Alumina dissolution KW - Rietveld analysis PY - 2009 U6 - https://doi.org/10.1111/j.1551-2916.2009.03089.x SN - 0002-7820 SN - 1551-2916 VL - 92 IS - 8 SP - 1703 EP - 1708 PB - Blackwell Publishing CY - Malden AN - OPUS4-20676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Meszaros, R. A1 - Rosemann, Maik A1 - Eberstein, M. A1 - Müller, Ralf A1 - Deubener, J. T1 - Dissolution of Alumina, Sintering and Crystallization in Glass Ceramic Composites for LTCC T2 - Intern. Con. on Glass ICG 2010 CY - Bahia, Brazil DA - 2010-09-20 PY - 2010 AN - OPUS4-22293 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winkel, A. A1 - Meszaros, R. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Travitzky, N. A1 - Fey, T. A1 - Greil, P. A1 - Wondraczek, L. T1 - Sintering of 3D-printed glass/HAp composites N2 - We report the sintering of 3D-printed composites of 13-93 bioactive glass and hydroxyapatite (HAp) powders. The sintering process is characterized on conventionally produced powder compacts with varying HAp content. A numeric approximation of the densification kinetics is then obtained on the basis of Frenkel, Mackenzie–Shuttleworth, and Einstein–Roscoe models, and optimized sintering conditions for 3D-printed structures are derived. Fully isotropic sintering of complex cellular composites is obtained by continuous heating to 750°C at a rate of 2 K/min for a HAp content of 40 wt%. The approach can readily be generalized for printing and sintering of similar glass-ceramic composites. KW - Sintering glass composit bio material PY - 2012 U6 - https://doi.org/10.1111/j.1551-2916.2012.05368.x SN - 0002-7820 SN - 1551-2916 VL - 95 IS - 11 SP - 3387 EP - 3393 PB - Blackwell Publishing CY - Malden AN - OPUS4-27053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Müller, Ralf A1 - Reinsch, Stefan ED - Bansal, N. P. ED - Boccaccini, A.R. T1 - Viscous-phase silicate processing KW - Viskoses Sintern KW - Oberflächenkeimbildung KW - Glaspulver KW - Sintermodelle KW - Sinterglaskeramik KW - Glasmatrixkomposit PY - 2012 SN - 978-0-470-55344-2 IS - Chapter 3 SP - 75 EP - 144 PB - Wiley AN - OPUS4-27054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Behrens, H. T1 - Internal friction of hydrated soda-lime-silicate glasses N2 - The internal friction of hydrated soda-lime-silica glasses with total water content (CW ) up to 1.9 wt. % was studied by dynamic mechanical analysis (DMA) using temperature-frequency sweeps from 723 K to 273 K and from 1 s-1 to 50 s-1. Total water content and concentrations of H2O molecules (CH2O ) and OH groups (COH) in the DMA specimens were determined by infrared spectroscopy. For low water contents (CW ≈ COH < 0.25 wt. %) two discrete internal friction peaks below the glass transition (α relaxation) were assigned to the low-temperature motion of alkali ions (γ relaxation) and cooperative movements of dissimilar mobile species under participation of OH at higher temperature (βOH relaxation). For large water contents (CW > 1 wt. %), where significant amounts of molecular water are evident (CH2O > 0.15 wt. %), however, internal friction spectra change unexpectedly: the βOH peak heights saturate and a low temperature shoulder appears on the β-relaxation peak. This emerging relaxation mode (βH2O relaxation) was assigned to the motions of H2O molecules. βH2O relaxation was found to be faster than βOH but slower than γ relaxation. Activation energy of the different relaxation modes increased in the order γ < βH2O < βOH < α. KW - Internal friction KW - Glass KW - Water content PY - 2013 U6 - https://doi.org/10.1063/1.4828740 SN - 0021-9606 SN - 1089-7690 VL - 139 SP - 174506-1 EP - 174506-6 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-29698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Rothe, Stefan A1 - Erfurt, Darja A1 - Müller, Ralf T1 - Mahlung und Sinterkristallisation von Erdalkalisilicatglas-Pulvern T2 - Fachausschuss I Physik und Chemie des Glases der DGG CY - Jena, Germany DA - 2013-10-08 PY - 2013 AN - OPUS4-29832 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Rothe, Stefan A1 - Erfurt, Darja A1 - Müller, Ralf T1 - Effects of milling on sinter-crystallization of alkaline earth silicate glass powders T2 - 23rd International Congress on Glass, ICG Prague 2013 CY - Prague, Czech Republic DA - 2013-07-01 PY - 2013 AN - OPUS4-28877 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tielemann, Christopher A1 - Reinsch, Stefan A1 - Maaß, Robert A1 - Deubener, J. A1 - Müller, Ralf T1 - Internal nucleation tendency and crystal surface energy obtained from bond energies and crystal lattice data N2 - We present an easy-to-apply method to predict structural trends in the internal nucleation tendency of oxide glasses. The approach is based on calculated crystal fracture surface energies derived from easily accessible diatomic bond energy and crystal lattice data. The applicability of the method is demonstrated on literature nucleation data for isochemically crystallizing oxide glasses. KW - Glass KW - Nucleation tendency KW - Fracture surface energy KW - Crystal lattice KW - Bond energy PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-548814 SN - 2590-1591 VL - 14 SP - 1 EP - 5 PB - Elsevier B.V. AN - OPUS4-54881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Tielemann, Christopher A1 - Müller, Ralf A1 - Busch, R. A1 - Patzig, C. A1 - Höche, T. T1 - Surface-Initiated Microstructure Formation in Glass Ceramics N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass KW - Oriented surface crystallization KW - Surface energy KW - Bond energy KW - Nucleation mode PY - 2022 AN - OPUS4-56070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Chen, Y.-F. A1 - Contreras Jaimes, A. T1 - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas (GlasDigital) N2 - Das Projekt GlasDigital wurde im allgemeinen vorgestellt, sowie die einzelnen Zwischenstände der verschiedenen Arbeitspakete aller Projektpartner präsentiert. Die allgemeine Porjektvorstellung ist auf deutsch. Die Zwischenstände der Arbeitsinhalte sind auf englisch. T2 - PMD Vollversammlung CY - Berlin, Germany DA - 03.11.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage KW - ML KW - Ontologie KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tielemann, Christopher A1 - Busch, R. A1 - Reinsch, Stefan A1 - Patzig, C. A1 - Höche, T. A1 - Avramov, I. A1 - Müller, Ralf T1 - Oriented surface nucleation in diopside glass N2 - Es wird die Texturbildung in kristallisierendem Diopsidglas im Zusammenhang mit der Oberflächenbeschaffenheit der unbehandelten Probe untersucht. Zudem wird der diskutiert, dass es sich bei der Texturbildung in Gläsern höchstwahrscheinlich um ein Nukleationsphänomen handelt welches auf die richtungsabhängige Grenzflächenenergie der kristallisierenden Phase zurückzuführen ist. N2 - Oriented surface crystallization on polished diopside glass surfaces has been studied with scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy and laser scanning microscopy. An orientation preference of [001] parallel to the glass surface was detected for separately growing diopside crystals even as small as 700 nm in size. This finding shows that crystal orientation occurs in the outermost surface layer without crystal-crystal interaction and indicates that the crystal orientation is a result of oriented nucleation. Depending on surface preparation, monomodal crystal orientation distributions with [100] perpendicular to the surface or bimodal distributions with [100] and [010] perpendicular to the glass Surface were detected. It was also shown that the degree of crystal orientation increases with decreasing Surface roughness. The observed orientation of diopside crystals could be explained in terms of the interfacial energies of different crystal faces. KW - Surface energy KW - Glass ceramic KW - Glass KW - EBSD KW - Diopsid PY - 2021 UR - https://www.sciencedirect.com/science/article/pii/S002230932100020X U6 - https://doi.org/10.1016/j.jnoncrysol.2021.120661 SN - 0022-3093 VL - 562 PB - Elsevier B.V. AN - OPUS4-53073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Busch, R. A1 - Tielemann, Christopher A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Patzig, C. A1 - Krause, M. A1 - Höche, T. T1 - Sample preparation for analytical scanning electron microscopy using initial notch sectioning N2 - A novel method for broad ion beam based sample sectioning using the concept of initial notches is presented. An adapted sample geometry is utilized in order to create terraces with a well-define d step in erosion depth from the surface. The method consists of milling a notch into the surface, followed by glancing-angle ion beam erosion, which leads to preferential erosion at the notch due to increased local surface elevation. The process of terrace formation can be utilized in sample preparation for analytical scanning electron microscopy in order to get efficient access to the depth-dependent microstructure of a material. It is demonstrated that the method can be applied to both conducting and non-conducting specimens. Furthermore, experimental parameters influencing the preparation success are determined. Finally, as a proof-of-concept, an electron backscatter diffraction study on a surface crystallized diopside glass ceramic is performed, where the method is used to analyze orientation dependent crystal growth phenomena occurring during growth of surface crystals into the bulk. KW - 3D etching KW - Ion beam erosion Sectioning KW - EBSD KW - Sample preparation KW - Analytical scanning electron microscopy KW - SEM KW - Glass Ceramic KW - Glass KW - Diopsid PY - 2021 U6 - https://doi.org/10.1016/j.micron.2021.103090 SN - 0968-4328 VL - 150 PB - Elsevier B.V. AN - OPUS4-53075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Ralf A1 - Behrens, Harald A1 - Ageo-Blanco, Boris A1 - Reinsch, Stefan A1 - Wirth, Thomas T1 - Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants N2 - Barium silicate glass powders 4 h milled in CO2 and Ar and sintered in air are studied with microscopy, total carbon analysis, differential thermal Analysis (DTA), vacuum hot extraction mass spectroscopy (VHE-MS), Fourier-transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary-ion mass spectrometry (TOF-SIMS). Intensive foaming of powder compacts is evident, and VHE studies prove that foaming is predominantly caused by carbonaceous species for both milling gases. DTA Shows that the decomposition of BaCO3 particles mix-milled with glass powders occurs at similar temperatures as foaming of compacts. However, no carbonate at the glass surface could be detected by FTIR spectroscopy, XPS, and TOF-SIMS after heating to the temperature of sintering. Instead, CO2 molecules unable to rotate identified by FTIR spectroscopy after milling, probably trapped by mechanical dissolution into the glass bulk. Such a mechanism or microencapsulation in cracks and particle aggregates can explain the contribution of Ar to foaming after intense milling in Ar atmosphere. The amount of CO2 molecules and Ar, however, cannot fully explain the extent of foaming. Carbonates mechanically dissolved beneath the surface or encapsulated in cracks and micropores of particle aggregates are therefore probably the major foaming source. KW - Milling KW - Foaming KW - Glass powder KW - Sintering PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-531227 SN - 1438-1656 VL - 24 IS - 6 SP - 2100445-1 EP - 2100445-13 AN - OPUS4-53122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Rouxel, T. A1 - Behrens, H. A1 - Deubener, J. A1 - Müller, Ralf T1 - Vacuum crack growth in alkali silicate glasses N2 - Crack growth velocity in alkali silicate glasses was measured in vacuum across 10 orders of magnitude with double cantilever beam technique. Measured and literature crack growth data were compared with calculated intrinsic fracture toughness data obtained from Young´s moduli and the theoretical fracture surface energy estimated from chemical bond energies. Data analysis reveals significant deviations from this intrinsic brittle fracture behavior. These deviations do not follow simple compositional trends. Two opposing processes may explain this finding: a decrease in the apparent fracture surface energy due to stress-induced chemical changes at the crack tip and its increase due to energy dissipation during fracture. KW - Silicate glass KW - Brittle fracture KW - Crack growth KW - Calculated intrinsic fracture toughness PY - 2021 U6 - https://doi.org/10.1016/j.jnoncrysol.2021.121094 SN - 0022-3093 VL - 572 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-53144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fest, Sarah Ute A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Milling, sintering and crystallization of 11BaO-25CaO-64SiO2 glass powder N2 - The crystallization of 11BaO-25CaO-64SiO2 mol% glass powders and related effects of glass powder milling have been studied by X-ray diffraction (XRD), light and scanning electron microscopy (SEM) and differential thermal analysis (DTA). Glass powders were made by ZrO2 crushing with subsequent sieving or sedimentation or alternatively made by milling with agate, corundum and tungsten carbide. Although surface crystallization was detectable during late sintering, all powders fully sintered. Wollastonite was found as primary crystal phase followed by cristobalite and sanbornite precipitation. The latter crystallization steps caused a second DTA-peak for fine powders. DTA-peak temperatures shifted to lower temperature with decreasing particle size in any case. No significant effects of milling materials on DTA-peak temperatures were evident. As an exception, however, milling in agate caused strongly decreased temperatures of the second DTA-peak. This observation can be explained by the progressive mechanical damaging, which results from the required prolonged milling time with agate due to its small materials density, and the fact that diamond made scratches did promote surface crystallization of cristobalite. The present study thus shows that even for glass powders with excellent sinterability, milling can affect microstructure evolution. KW - Glass KW - Crystallization KW - Powder preparation KW - SOFC PY - 2014 UR - http://onlinelibrary.wiley.com/doi/10.1111/ijag.12080/full U6 - https://doi.org/10.1111/ijag.12080 SN - 2041-1286 SN - 2041-1294 VL - 5 IS - 3 SP - 236 EP - 247 PB - Wiley-Blackwell CY - Hoboken, NJ [u.a.] AN - OPUS4-30807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Agea Blanco, Boris A1 - Müller, Ralf T1 - Sintering and bloating phenomena of barium disilicate glass powders T2 - 88. Glastechnische Tagung DGG - ACerS GOMD 2014 CY - Aachen, Germany DA - 26.05.2014 PY - 2014 AN - OPUS4-30810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Fest, Sarah Ute A1 - Müller, Ralf T1 - Effects of milling on sinter-crystallization of alkaline earth silicate glass powders T2 - 88. Glastechnische Tagung DGG - ACerS GOMD 2014 CY - Aachen, Germany DA - 2014-05-26 PY - 2014 AN - OPUS4-30811 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eberstein, Markus A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Schiller, Wolfgang Arno T1 - Sintering of glass matrix composites with small rigid inclusions KW - Glass ceramics KW - Inclusions KW - Sintering KW - Mixing KW - Powders KW - Solid-state reaction PY - 2009 U6 - https://doi.org/10.1016/j.jeurceramsoc.2009.02.007 SN - 0955-2219 SN - 1873-619X VL - 29 IS - 12 SP - 2469 EP - 2479 PB - Elsevier CY - Oxford AN - OPUS4-19570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Gaber, Martin A1 - Güther, Wolfgang A1 - Müller, Ralf A1 - Schiller, Wolfgang Arno T1 - Gassensorgeregelte Entbinderung keramischer Folien T2 - Symp. HLK 2009 CY - Aachen, Germany DA - 2009-03-23 PY - 2009 AN - OPUS4-18965 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Reinsch, Stefan A1 - Schadrack, Reinhard A1 - Benemann, Sigrid T1 - Burnout behavior of ceramic coated open cell polyurethane (PU) sponges N2 - Open cell rigid foams made from polyurethane (PU) are frequently used in ceramic processing for preparation of porous ceramics by the so-called replica technique. This work presents data regarding the PU burnout, shrinkage characteristics as well as the morphology of the ceramic coated PU sponges during heating up. Shrinkage of the ceramic coated PU sponges closely follows the mass loss due to PU decomposition. Two temperatures (i) 267 °C and (ii) 380 °C were identified at which PU decomposition reaches local maxima. Shrinkage measurements on ceramic coated PU sponges reveal that both PU decomposition stages lead to similar extends of shrinkage in the ceramic coated PU sponge. Differential thermal analysis (DTA) showed that the two decomposition related temperatures (267 and 380 °C) differ concerning the energy release. While the low-temperature signal is endothermic, an exothermic signal was detected at 380 °C. The morphology of the ceramic coated PU sponges was investigated with scanning electron microscopy (SEM) which gave insight into the formation of hollow ceramic struts-a well known feature of ceramics being prepared by the replica technique. KW - Polyurethane (PU) KW - Porous ceramics KW - Mass spectrometry KW - Thermal analysis PY - 2009 U6 - https://doi.org/10.1016/j.jeurceramsoc.2009.07.025 SN - 0955-2219 SN - 1873-619X VL - 29 IS - 16 SP - 3333 EP - 3339 PB - Elsevier CY - Oxford AN - OPUS4-20092 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Klobes, Peter A1 - Dörfel, Ilona A1 - Reinsch, Stefan T1 - Differences between films and monoliths of sol-gel derived aluminas N2 - This work compares thin layers (films) and monoliths prepared from alumina sols with respect to their microstructure, thermal evolution, porosity and specific surface area. After heat treatment at similar temperatures, films and monoliths showed the same qualitative changes in porosity and specific surface area. However, some marked quantitative differences were detected. Film fragments had a lower open porosity, a lower specific surface area and a narrower pore size distribution. Furthermore, the thermal evolution showed a markedly different burnout of organic components between films and monoliths. The observed differences between films and monolith can be explained by the ageing history of the sols during sample preparation. KW - Sol-gel processing KW - Alumina KW - Phase transitions KW - Porosity PY - 2010 U6 - https://doi.org/10.1016/j.tsf.2010.07.057 SN - 0040-6090 VL - 519 IS - 1 SP - 42 EP - 51 PB - Elsevier CY - Amsterdam AN - OPUS4-22606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Deubener, J. A1 - Bornhöft, H. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Lumeau, J. A1 - Glebova, L.N. A1 - Glebov, L.B. T1 - Viscosity, relaxation and elastic properties of photo-thermo-refractive glass KW - Ultrasonic relaxation KW - Silicates KW - Rheology KW - Structural relaxation KW - Viscosity PY - 2009 U6 - https://doi.org/10.1016/j.noncrysol.2008.10.002 SN - 0022-3093 VL - 355 SP - 126 EP - 131 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schiller, Wolfgang Arno A1 - Müller, Ralf A1 - Eberstein, Markus A1 - Reinsch, Stefan A1 - Rabe, Torsten T1 - Sintering of LTCC N2 - Low Temperature Co-fired Ceramic materials (LTCC) have attracted growing interest in recent years since they are promising candidates for highly integrated ceramic packaging. This paper surveys materials concepts of related glass ceramic composites (GCC) and discusses unsolved problems and challenges. The densification of GCC based on "viscous sintering" may be affected by steric effects and partial dissolution of dispersed crystal particles, crystallization and phase boundary reactions. KW - Sintering KW - Glass ceramic composites KW - Viscosity KW - Densification KW - Modelling PY - 2008 SN - 0173-9913 SN - 0196-6219 VL - 85 IS - 13 SP - 12 EP - 17 PB - Göller CY - Baden-Baden AN - OPUS4-19086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Schmidt, I. A1 - Müller, Ralf A1 - Kraft, T. A1 - Deubener, J. T1 - Sinterkinetik von Glasmatrixkompositen für Low Temperature Co-fired ceramics T2 - 83. Glastechnische Tagung CY - Amberg, Germany DA - 2009-05-18 PY - 2009 AN - OPUS4-21411 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agea Blanco, Boris A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Sintering and foaming of barium silicate glass powder compacts N2 - The manufacture of sintered glasses and glass-ceramics, glass matrix composites, and glass-bounded ceramics or pastes is often affected by gas bubble formation. Against this background, we studied sintering and foaming of barium silicate glass powders used as SOFC sealants using different powder milling procedures. Sintering was measured by means of heating microscopy backed up by XPD, differential thermal analysis, vacuum hot extraction (VHE), and optical and electron microscopy. Foaming increased significantly as milling progressed. For moderately milled glass powders, subsequent storage in air could also promote foaming. Although the powder compacts were uniaxially pressed and sintered in air, the milling atmosphere significantly affected foaming. The strength of this effect increased in the order Ar ≈ N2 < air < CO2. Conformingly, VHE studies revealed that the pores of foamed samples predominantly encapsulated CO2, even for powders milled in Ar and N2. Results of this study thus indicate that foaming is caused by carbonaceous species trapped on the glass powder surface. Foaming could be substantially reduced by milling in water and 10 wt% HCl. KW - Glass powder KW - Sintering KW - Foaming KW - SOFC PY - 2016 UR - http://journal.frontiersin.org/article/10.3389/fmats.2016.00045/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Materials&id=214488 U6 - https://doi.org/10.3389/fmats.2016.00045 SN - 2296-8016 VL - 3 SP - Article 45, 1 EP - 10 AN - OPUS4-38303 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Roessler, C. A1 - Bauer, Ute A1 - Behrens, H. T1 - Glass transition and viscosity of hydrous soda-lime-borate glasses N2 - Boron oxide glasses usually show low glass transition temperature Tg due to the three-fold oxygen coordination of boron. Adding of alkali and alkaline earth oxides to the glass composition will not decrease but increase Tg due to a change in boron coordination from trigonal to tetrahedral, known as the boron anomaly. Only for higher fractions of alkali oxides, non-bridging oxygens (NBO) are progressively formed in competition with tetrahedrally coordinated boron, which leads to a decrease in viscosity. ln contrast to this well-known behavior of alkali oxides (R2O), there is little known about adding H2O to borate glasses. The present work therefore aims in shedding light on the rheological properties of hydrous soda lime borate glasses with particular focus on the role of water. For doing so, we determined Tg as a function of Na2O and H2O content using differential thermal analysis (DTA) backed up by micropenetration viscosity measurements. Results show that water decreases Tg for all glasses and water concentrations under study (< 8 wt.% total water). Obviously, water mostly causes the formation of NBO having no significant influence on boron coordination as seen for alkaline. T2 - Crystallization 2015 CY - Shanghai, China DA - 07.04.2016 KW - Borate glasses KW - Thermal analyses KW - Viscosity KW - Water-bearing glasses PY - 2016 AN - OPUS4-38318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Bauer, Ute A1 - Roessler, Ch. A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Mechanical spectroscopy studies on hydrous borate and silicate glasses T2 - ACERS GOMD-DGG 2015 CY - Miami, USA DA - 2015-05-17 PY - 2015 AN - OPUS4-34529 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Roessler, Ch. A1 - Bauer, Ute A1 - Müller, Ralf A1 - Deubener, J. A1 - Behrens, H. T1 - Water-boron speciation in hydrous soda-lime borate glasses T2 - GeoBerlin 2015 CY - Berlin, Germany DA - 2015-10-05 PY - 2015 AN - OPUS4-34530 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Deubener, J. A1 - Behrens, H. T1 - DMTA study of hydrated soda-lime-silicate glasses T2 - Thermal Analysis and Calorimetry in Industry and Research - 40 Years of GEFTA CY - Berlin, Germany DA - 2014-09-16 PY - 2014 AN - OPUS4-32343 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Bauer, Ute A1 - Rößler, C. A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - The role of volatiles in mechanical behavior of oxide glasses: II. Mechanical spectroscopy studies on hydrous glasses T2 - FFAG-6, 6th International Workshop on Flow and Fracture of Advanced Glasses CY - Weimar, Germany DA - 2014-10-07 PY - 2014 AN - OPUS4-32341 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bauer, Ute A1 - Behrens, H. A1 - Fechtelkord, M. A1 - Reinsch, Stefan A1 - Deubener, J. T1 - Water- and boron speciation in hydrous soda-lime-borate glasses N2 - The structural investigation of hydrated borate glasses provides new insights on the influence of water on boron speciation using spectroscopic methods. In the present study three soda–lime–borate glasses (NCBx with x = 5, 15 and 25 corresponding to xNa2O, 10CaO, 90 - xB2O3 in mol%) were prepared with water content up to 8 wt.%. The water speciation in the glasses was derived by near-infrared (NIR) spectroscopy while boron speciation was investigated by 11B MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance). For the three glasses effective molar absorption coefficients were determined experimentally for the bands at 5200 cm- 1 and 4600 cm- 1, corresponding to combination modes of H2O molecules and OH-groups, respectively. In contrast to silicate glasses, in which at most ~ 2 wt.% H2O are dissociated to OH-groups, the amount of dissociated H2O may even exceed 5 wt.% in borate glasses. The fraction of tetrahedral to total boron (N4 = BIV / BIV + BIII) is predominantly controlled by the ratio of Na2O + CaO / B2O3, but only weakly affected by the water content of the glasses. When increasing the H2O content from 0 to 8 wt.%, N4 increases from 25% to 26% for NCB5 and from 42% to 47% for NCB25 glasses. KW - Glass structure KW - Water-bearing glasses KW - High pressure KW - Spectroscopy KW - Glasstruktur KW - Wasserhaltige Gläser KW - Hoher Druck KW - Spektroskopie PY - 2015 U6 - https://doi.org/10.1016/j.jnoncrysol.2015.05.004 SN - 0022-3093 VL - 423-424 SP - 58 EP - 67 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-33804 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Rössler, Christian A1 - Bauer, Ute A1 - Müller, Ralf A1 - Deubener, Joachim A1 - Behrens, Harald T1 - Wasser, der andere Netzwerkwandler in Boratgläsern N2 - Boratgläser zeigen im allgeneinen eine niedrige Glasübergangstemperatur, Tg, auf Grund der 3fach Koordination des Bors mit Sauerstoff. Der Zusatz von Alkali- und Erdalkalioxiden zur Glaszusammensetzung führt zunächst zu einem Anstieg von Tg auf Grund des Koordinationswechsels des Bors von der 3fach zur 4fach Koordination, was als Borsäureanomalie bekannt ist. Bei hohen Alkalioxidgehalten werden dann zunehmend Nichtbrückensauerstoffe (NBO) auf Kosten des tetraedrisch koordinierten Bor gebildet, was zur Senkung der Viskosität führt. Im Gegensatz zu diesem bekannten Verhalten der Alkalioxide (R2O) ist wenig über die Wirkung von Wasser in Boratgläsern bekannt. Daher sollen in dieser Arbeit die rheologischen Eigenschaf-ten von wasserreichen Kalk-Natron-Boratgläsern unter spezieller Berücksichtigung der Rolle des Wassers näher betrachtet werden. Zu diesem Zweck wurde Tg in Abhängigkeit des Na2O- und H2O-Gehalts mittels Differentialthermoanalyse (DTA) und Mikropenetrationsviskosimetrie untersucht. Die Ergebnisse zeigen, dass im Gegensatz zu Na2O Wasser in allen untersuchten Glä-sern und H2O-Konzentrationsbereichen (< 8 Gew.%) Tg deutlich verringert. Diese Beobachtung weist darauf hin, dass Wasser primär zur Bildung von NBO führt und kaum zu einem Koordina-tionswechsel des Bors beiträgt. T2 - 90. Glastechnische Tagung der Deutsche Glastechnische Gesellschaft e.V. CY - Goslar, Germany DA - 06.06.2016 KW - Wasserhaltige Gläser KW - Viskosität KW - Boratglas KW - Thermische Analyse PY - 2016 AN - OPUS4-38380 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Patzig, C. T1 - Surface-initiated microstructure formation in glass ceramics N2 - Up to now, the mechanisms of surface nucleation and surface-induced texture formation are far from being understood. Corresponding phenomena are discussed hypothetically or even controversial, and related studies are restricted to very few glasses. As a main drawback, the vast majority of previous work on oriented growth of surface crystals do not consider the possible effects of glass surface treatments (like polishing defects, adhered particles and cracks, …) or ambient annealing conditions (vacuum or atmospheric pressure) which both can influence crystal nucleation and growth. Moreover, very few observations of crystal orientation related to surface crystallization were focused on separately growing crystals. In conclusion, up to now, no systematic studies on initially oriented crystal growth or nucleation from defined active nucleation sites have been pursued. Therefore, the main objective of the proposed project is to gain a basic understanding of the mechanisms of surface-induced microstructure formation in glass ceramics. We shall answer the question whether preferred orientation of surface crystals is the result of oriented nucleation or caused by other orientation selection mechanisms acting during early crystal growth. In both cases, crystal orientation may be caused by the orientation of the glass surface itself or the anisotropy and orientation of active surface nucleation defects. New techniques of experimental characterization of surface-crystallized glasses shall be applied to find answers to the questions posed above. Based on a controlled preparation and annealing of the glass sample surfaces, that includes the defined creation of active nucleation defects, and followed by the microstructural characterization especially during the very early growth stages of separated surface crystals, the orientation relations between defect and initiated surface crystal will be analyzed. In order to gain new insights, a couple of entirely new microstructure diagnostics techniques, including chemically contrasted XRM, laser-based sample preparation for XRM, and 3D electron backscatter diffraction shall be developed or applied. This way, using X-ray microscopy as a pivotal technique for the non-destructive 3D characterization of relatively large samples at superior spatial resolution (but also complemented by other microstructure diagnostics techniques, e.g. TEM elemental mappings at cross-sectioned samples) unprecedented insights into the microstructure evolution upon surface crystallization of model glasses will be gained. T2 - DFG Begutachtungskolloquium (PAK 949/1 und PAK 950/1) CY - Bonn, Germany DA - 07.03.2017 KW - Oberflächenkeimbildung KW - Glaskeramik KW - Orientierung PY - 2017 AN - OPUS4-44219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Patzig, C. T1 - Surface-initiated microstructure formation in glass ceramics N2 - Up to now, the mechanisms of surface nucleation and surface-induced texture formation are far from being understood. Corresponding phenomena are discussed hypothetically or even controversial, and related studies are restricted to very few glasses. As a main drawback, the vast majority of previous work on oriented growth of surface crystals do not consider the possible effects of glass surface treatments (like polishing defects, adhered particles and cracks, …) or ambient annealing conditions (vacuum or atmospheric pressure) which both can influence crystal nucleation and growth. Moreover, very few observations of crystal orientation related to surface crystallization were focused on separately growing crystals. In conclusion, up to now, no systematic studies on initially oriented crystal growth or nucleation from defined active nucleation sites have been pursued. Therefore, the main objective of the proposed project is to gain a basic understanding of the mechanisms of surface-induced microstructure formation in glass ceramics. We shall answer the question whether preferred orientation of surface crystals is the result of oriented nucleation or caused by other orientation selection mechanisms acting during early crystal growth. In both cases, crystal orientation may be caused by the orientation of the glass surface itself or the anisotropy and orientation of active surface nucleation defects. New techniques of experimental characterization of surface-crystallized glasses shall be applied to find answers to the questions posed above. Based on a controlled preparation and annealing of the glass sample surfaces, that includes the defined creation of active nucleation defects, and followed by the microstructural characterization especially during the very early growth stages of separated surface crystals, the orientation relations between defect and initiated surface crystal will be analyzed. In order to gain new insights, a couple of entirely new microstructure diagnostics techniques, including chemically contrasted XRM, laser-based sample preparation for XRM, and 3D electron backscatter diffraction shall be developed or applied. This way, using X-ray microscopy as a pivotal technique for the non-destructive 3D characterization of relatively large samples at superior spatial resolution (but also complemented by other microstructure diagnostics techniques, e.g. TEM elemental mappings at cross-sectioned samples) unprecedented insights into the microstructure evolution upon surface crystallization of model glasses will be gained. T2 - DFG Begutachtungskolloquium (PAK 949/1 und PAK 950/1) CY - Bonn, Germany DA - 07.03.2017 KW - Oberflächenkeimbildung KW - Glaskeramik KW - Orientierung PY - 2017 AN - OPUS4-44221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wisniewski, W. A1 - Thieme, C. A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Groß-Barsnick, S.-M. A1 - Rüssel, C. T1 - Oriented surface nucleation and crystal growth in a 18BaO·22CaO·60SiO2 mol% glass used for SOFC seals N2 - A glass of the composition 37BaO·16CaO·47SiO2 wt% produced on an industrial scale is crystallized at 970 °C for times ranging from 15 min to 2 h. The crystallization at the immediate surface as well as the crystal growth into the bulk are analyzed using scanning electron microscopy (SEM) including energy dispersive X-ray spectroscopy (EDXS) and electron backscatter diffraction (EBSD) as well as X-ray diffraction in the Θ–2Θ setup (XRD). The immediate surface shows the oriented nucleation of walstromite as well as the formation of wollastonite and an unknown phase of the composition BaCaSi3O8. All three phases also grow into the bulk where walstromite ultimately dominates the kinetic selection and grows throughout the bulk due to a lack of bulk nucleation. Walstromite shows systematic orientation changes as well as twinning during growth. A critical analysis of the XRD-patterns acquired from various crystallized samples indicates that their evaluation is problematic and that phases detected by XRD in this system should be verified by another method such as EDXS. KW - Glass KW - Surface nucleation KW - Orientation KW - EBSD PY - 2018 U6 - https://doi.org/10.1039/c7ce02008b VL - 20 IS - 6 SP - 787 EP - 795 PB - Royal Society of Chemistry AN - OPUS4-44405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Surface-induced Crystallization of Glass N2 - Up to now, the mechanisms of surface nucleation and surface-induced texture formation are far from being understood. Corresponding phenomena are discussed hypothetically or even controversial, and related studies are restricted to very few glasses. In this talk the state of the art on mechanisms of surface nucleation are summarized. On one hand, mechanical damaged surfaces show high nucleation activity, at which the nucleation occurs at convex tips and edges preferentially. On the other hand, solid foreign particles are dominant nucleation sites at low damaged surfaces. They enable nucleation at temperatures even far above Tg. The nucleation activity of the particles is substantially controlled by their thermal and chemical durability. But no systematic studies on initially oriented crystal growth or nucleation from defined active nucleation sites have been pursued, so far. Therefore, the main objective of a just started project is to advance the basic understanding of the mechanisms of surface-induced microstructure formation in glass ceramics. We shall answer the question whether preferred orientation of surface crystals is the result of oriented nucleation or caused by other orientation selection mechanisms acting during early crystal growth. In both cases, crystal orientation may be caused by the orientation of the glass surface itself or the anisotropy and orientation of active surface nucleation defects. As a first attempt we focused on possible reorientation of separately growing surface crystals during early crystal growth. First results show clear evidence that separately growing crystals can reorient themselves as they are going to impinge each other. T2 - Glasforum der Deutschen Glastechnischen Gesellschaft (DGG) CY - Würzburg, Germany DA - 11.06.2018 KW - Crystallization KW - Silicate Glasses KW - Surface Nucleation PY - 2018 AN - OPUS4-45593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Behrens, H. A1 - Bauer, U. A1 - Reinsch, Stefan A1 - Kiefer, P. A1 - Müller, Ralf A1 - Deubener, J. T1 - Structural relaxation mechanisms in hydrous sodium borosilicate glasses N2 - Borosilicate glasses (16Na2O–10B2O3–74SiO2, NBS) with water contents up to 22 mol% H2O were prepared to study the effect of water on structural relaxation using DTA, viscometry and internal friction measurements. The results show that the glass transition temperature Tg of DTA and the isokom temperature T12, of viscometry are in excellent agreement, confirming the equivalence of enthalpy and viscous relaxation for NBS glass. Combining Tg data with water speciation data demonstrates that OH groups are mainly responsible for the decrease of Tg with increasing hydration, while molecular water plays only a minor role. Internal friction spectra at 7.125 Hz confirm the decisive influence of water on mechanical relaxation. The temperature range of α-relaxation (glass transition) strongly decreases while two β-relaxation peaks (sub-Tg) progressively appear with increasing water content. A high temperature β-relaxation peak, attributed to the presence of OH groups, shifts from 670 to 450 K as total water content increases from 0.01 to 5 wt%. A low temperature β-relaxation peak, attributed to molecular water, appears at 380 K and 330 K in glasses containing 3 and 5 wt% H2O, respectively. These findings suggest that relaxation mechanism of different hydrous species at low temperature may contribute to fatigue of stressed glasses. KW - Borosilicate glass KW - Water KW - Relaxation KW - Internal friction KW - Glass transition PY - 2018 U6 - https://doi.org/10.1016/j.jnoncrysol.2018.05.025 VL - 497 SP - 30 EP - 39 PB - Elsevier B.V. AN - OPUS4-45608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kiefer, P. A1 - Maiwald, M. A1 - Deubener, J. A1 - Balzer, R. A1 - Behrens, H. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Automated Analysis of Slow Crack Growth in Hydrous Soda-Lime Silicate Glasses N2 - To explore the impact of ambient and structural water on static fatigue, the initiation and growth of 3279 Vickers induced median radial cracks were automatically recorded and analyzed. We find that humidity is more efficient in initiating cracks and promoting their growth than water, which is dissolved in the glass structure. In particular for slow crack growth (< 3x10-6 m s-1), tests in dry nitrogen showed a considerable decrease in the crack growth exponent with increasing water content of the glasses. On the other hand, if tests were performed in humid air, the crack growth exponent was independent of the water content of the hydrous glasses, while stress intensity decreased slightly. These observations indicate that water promotes the processes at the crack-tip regardless of its origin. However, ambient water is more efficient. KW - Indentation fracture toughness KW - Slow crack growth KW - Automated analysis KW - Hydrous glass KW - Vickers indentation PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-513085 VL - 7 SP - 268 AN - OPUS4-51308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balzer, R. A1 - Behrens, H. A1 - Reinsch, Stefan A1 - Fechtelkord, M. T1 - Structural investigation of hydrous phosphate glasses N2 - Dissolved water has major impact on the physical and chemical properties of phosphate glasses. In the present study we have investigated the structural response to water incorporation for glasses in the system Li2O–MgO–Al2O3–P2O5. Glasses containing 0–8 wt% H2O were synthesised at 500 MPa confining pressure in internally heated gas pressure vessels at 1323 K (LMP, Al-poor glass) and 1423 K (LMAP, Al-enriched glass). Water contents of glasses were determined by pyrolysis and subsequent Karl-Fischer titration (KFT) and/or by infrared spectroscopy. Density varies nonlinearly with water content implying large structural changes when adding up to 2 wt% H2O to the dry glass. Glass Transition temperatures measured by differential thermal analysis (DTA) continuously decrease with water content. The trend can be explained by depolymerisation of the phosphate network. Near-infrared spectroscopy shows that even in Al poor glasses only a minority of dissolved water is present as H2O molecules, but the largest amount is present as OH Groups formed by hydrolysis of P–O–P bonds. The network is stabilised by aluminium which is predominantly six-coordinated in these glasses as shown by 27Al MAS NMR spectroscopy. With increase of Al in the glasses, breaking up of the Phosphate network through hydrolysis is depressed, i.e. much lower OH Contents are formed at same total water content. Network depolymerisation upon addition of H2O is evident also from 31P MAS NMR spectroscopy. While Phosphate tetraheda are crosslinked by two to three bridging oxygen in dry glasses, diphosphate Groups are dominant in glasses containing 8 wt% H2O. T2 - 2. INT. CONF. ON PHOSPHATE GLASSES CY - Oxford, UK DA - 26.07.2017 KW - water speciation KW - phosphate glasses KW - infrared spectroscopy KW - NMR spectroscopy KW - high pressure PY - 2019 U6 - https://doi.org/10.13036/17533562.60.2.041 SN - 1753-3562 VL - 60 IS - 2 SP - 49 EP - 61 PB - Society of Glass Technology CY - Sheffield AN - OPUS4-48122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Agea-Blanco, Boris A1 - Blaeß, Carsten A1 - Waurischk, Tina T1 - Sintering and foaming of silicate glass powders N2 - Glass powders are promising candidates for manufacturing a broad diversity of sintered materials like sintered glass-ceramics, glass matrix composites, glass bonded ceramics or pastes. Powder processing, however, can substantially affect sinterability, e.g. by promoting surface crystallization. On the other hand, densification can be hindered by gas bubble formation for slow crystallizing glass powders. Against this background, we studied sintering and foaming of silicate glass powders with different crystallization tendency for wet milling and dry milling in air, Ar, N2, and CO2 by means of heating microscopy, DTA, Vacuum Hot Extraction (VHE), SEM, IR spectroscopy, XPS, and ToF-SIMS. In any case, foaming activity increased significantly with progressive milling. For moderately milled glass powders, subsequent storage in air could also promote foaming. Contrarily, foaming could be substantially reduced by milling in water and 10 wt% HCl. Although all powder compacts were uniaxially pressed and sintered in air, foaming was significantly affected by different milling atmosphere and was found most pronounced for milling in CO2 atmosphere. Conformingly, VHE studies revealed that foaming is mainly driven by carbonaceous species, even for powders milled in other gases. Current results of this study thus indicate that foaming is caused by carbonaceous species trapped on the glass powder surface. T2 - IMAPS/ACerS 15th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT 2019) CY - Shanghai, China DA - 16.04.2019 KW - Glass powder KW - Sintering KW - Foaming PY - 2019 AN - OPUS4-48196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Tielemann, Christopher A1 - Busch, R. A1 - Patzig, C. A1 - Müller, Ralf A1 - Höche, T. T1 - Oriented surface crystallization in 18BaO·22CaO·60SiO2 and MgO·CaO·2SiO2 glasses N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. The vast majority of previous work does not consider possible effects of surface preparation and surrounding atmosphere. Moreover, very few observations of surface crystal orientation were made on separately grown crystals. The aim of our project is to advance the basic understanding of oriented surface crystallization, e.g. whether preferred orientation of surface crystals results from oriented nucleation or reorientation mechanisms during early crystal growth. In both cases, crystal orientation may reflect the orientation of the glass surface or that of anisotropic active surface nucleation sites. Therefore, we focus on orientation of surface crystals separately growing under controlled conditions. First results on diopside (MgCaSi2O6) and walstromite (BaCa2Si3O9) crystals growing from 18BaO·22CaO·60SiO2 and MgO·CaO·2SiO2 glass surfaces, respectively, indicate that different orientation mechanisms may occur. Neighbored walstromite crystals were found to gradually reorient themselves when they are going to impinge each other during stepwise isothermal treatments (log η = 4,5 Pa*s) of polished glass samples. Nevertheless, no preferred crystal orientation was evident for separate crystals. For diopside crystals growing from polished glass surfaces (1 μm diamond lapping foil), strong preferred orientation was observed for 3.5 to 85 min annealing at 850 °C. Electron Backscatter Diffraction (EBSD) studies showed that the c-axis of surface crystals is oriented parallel to the glass surface and that separated diopside crystals as small as 600 nm are already oriented. Studies on glass surfaces, polished with diamond lapping foils starting from 16 μm down to 1 μm grain, revealed that crystal orientation may scatter arround this preferential orientation and that this scatter progressively decreases with decreasing polishing grain size. T2 - 93rd Annual Meeting of the German Society of Glass Technology (DGG) in conjunction with the French Union for Science and Glass Technology (USTV) Annual Meeting CY - Nuremberg, Germany DA - 13.05.2019 KW - Surface crystallization KW - Orientation KW - Glass KW - Diopside PY - 2019 AN - OPUS4-48198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balzer, R. A1 - Behrens, H. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Kiefer, P. A1 - Deubener, J. A1 - Fechtelkord, M. T1 - Water in Alkali Aluminosilicate Glasses N2 - To understand the influence of water and alkalis on aluminosilicate glasses, three polymerized glasses with varying ratios of Na/K were synthesized [(22. 5-x)Na2O-xK2O-22.5 Al2O3-55 SiO2 with x = 0, 7.5, and 11.25]. Subsequently, these glasses were hydrated (up to 8 wt% H2O) in an internally heated gas pressure vessel. The density of hydrous glasses linearly decreased with water content above 1 wt%, consistent with the partial molar volume of H2O of 12 cm3/mol. Near-infrared spectroscopy revealed that hydroxyl groups are the dominant species at water content of <4 wt%, and molecular water becomes dominating at water content of >5 wt%. The fraction of OH is particularly high in the pure Na-bearing glass compared to the mixed alkali glasses. 27Al magic angle spinning-NMR spectroscopy shows that aluminum is exclusively fourfold coordinated with some variations in the local geometry. It appears that the local structure around Al becomes more ordered with increasing K/Na ratio. The incorporation of H2O reinforces this effect. The differential thermal analysis of hydrous glasses shows a significant mass loss in the range of glass transition already during the first upscan, implying the high mobility of water in the glasses. This observation can be explained by the open structure of the aluminosilicate network and by the low dissociation enthalpy of H2O in the glasses (≈ 8 kJ/mol). The effect of the dissolved H2O on the glass transition temperature is less pronounced than for other aluminosilicate glasses, probably because of the large fraction of Al in the glasses. KW - NMR spectroscopy KW - Alkali aluminosilicate glasses KW - Water speciation KW - Glass transition KW - Infrared spectroscopy PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-509497 VL - 7 SP - 85 AN - OPUS4-50949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Kiefer, P. A1 - Deubener, J. A1 - Balzer, R. A1 - Behrens, H. T1 - Crack Growth in Hydrous Soda-Lime Silicate Glass N2 - Stable crack growth was measured for nominal dry and water-bearing (6 wt%) soda-lime silicate glasses in double cantilever beam geometry and combined with DMA studies on the effects of dissolved water on internal friction and glass transition, respectively. In vacuum, a decreased slope of logarithmic crack growth velocity versus stress intensity factor is evident for the hydrous glass in line with an increase of b-relaxation intensity indicating more energy Dissipation during fracture. Further, inert crack growth in hydrous glass is found to be divided into sections of different slope, which indicates different water related crack propagation mechanism. In ambient air, a largely extended region II is observed for the hydrous glass, which indicates that crack growth is more sensitive to ambient water. KW - Internal friction KW - Soda-lime silicate glass KW - Water content KW - Stable crack growth KW - DCB geometry KW - Stress intensity factor PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-506829 VL - 7 SP - Articel 66 AN - OPUS4-50682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agea Blanco, Boris A1 - Blaess, C. A1 - Reinsch, Stefan A1 - Brauer, D. A1 - Müller, Ralf T1 - Sintering and foaming of barium and calcium silicate glass powders N2 - Sintering and foaming of barium and calcium silicate glass powder compacts have been studied for different powder milling. Sintering was measured by means of heating microscopy backed up by XRD, DTA, Vacuum Hot Extraction (VHE) and electron microscopy. Foaming intensity strongly increased with decreasing glass partiefe size. Although powder compacts were uniaxially pressed and sintered in ambient air, foaming was affected by the milling atmosphere and most intensive for milfing in C02. Conformingly, VHE studies revealed that foaming of fully sintered samples was mainly driven by C02, even for powders milled in technical air, Ar and N2. Prolonged storage of air milled barium silicate glass powders in ambient air before pressing and sintering caused further increase of foaming intensity. These findings indicate that carbonaceous species are preferentially trapped to or close beneath the powder surface during milling and later storage. The temperature range of C02 degassing from fully sintered barium and calcium silicate g/ass powder compacts fits the temperature ranges of decomposition of BaC03 and CaC03 mix-milled with the respective barium and calcium silicate glass powders. T2 - IMAPS/ACerS 11th International CICMT conference and exhibition CY - Dresden, Germany DA - 20.04.2015 KW - Sintering KW - Foaming KW - Silicate glass powders KW - Barium and calcium silicate plass powders KW - Degassing PY - 2015 SN - 978-1510804562 SP - 31 EP - 37 AN - OPUS4-35250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Eberstein, Markus A1 - Müller, Ralf A1 - Schiller, Wolfgang Arno A1 - Schweiger, M. T1 - Lastabhängige Schwindung von Glaspulvern N2 - Glasig-kristalline Sinterwerkstoffe werden für vielfältige Anwendungen eingesetzt. Bei einem hohen Glasanteil ist ein Einfluss geringer Lasten auf das Schwindungsverhalten möglich, so dass es zu Fehlinterpretationen des Schwindungsverhaltens bei gebräuchlichen Horizontaldilatometer kommen kann. T2 - 75. Glasetechnische Tagung CY - Wernigerode, Germany DA - 21.05.2001 KW - Glasig-kristalline Sinterwerkstoffe KW - Schwindungsverhalten KW - Horizontaldilatometer PY - 2001 AN - OPUS4-35786 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Rössler, C. A1 - Bauer, Ute A1 - Müller, Ralf A1 - Deubener, J. A1 - Behrens, H. T1 - Water, the other network modifier in borate glasses N2 - In the present study we have investigated whether the effect of water on properties of borate glasses resembles that of alkali oxide. Soda-lime-borate glasses with nominal compositions of x Na2O, 10 CaO, (90-x) B2O3 (x = 5, 15 and 25 mol%) were doped with up to 8 wt.% H2O by processing glass powder + distilled water in platinum capsules in an internally heated gas pressure vessel at 1523 K and 500 MPa. The water content of hydrous glasses was determined by Karl-Fischer titration and near-infrared spectroscopy. The glass transition temperature T-g. was derived from DTA and micropenetration experiments for which the effect of water loss at the surface of the hydrous glasses was studied. Heating glass samples at 10 K min(-1) in the DTA resulted in T-g values which are close to T-12 isokom temperatures confirming the equivalence of enthalpy relaxation and viscous relaxation for borate glasses. For all three glass series it is shown that T-g strongly decreases whereas the liquid fragility strongly increases upon the addition of water. These findings reveal that H2O primarily causes breaking of B-O-B bonds rather than supporting 4-fold coordinated boron as it is well-known for alkali oxides in this concentration range. (C) 2015 Elsevier B.V. All rights reserved. KW - Wasserhaltige Gläser KW - Viskosität KW - Boratgläser KW - Thermische Analyse KW - Viscosity KW - Borate glasses KW - Thermal analysis KW - Water-bearing glasses PY - 2016 U6 - https://doi.org/10.1016/j.jnoncrysol.2015.10.010 SN - 0022-3093 VL - 432 SP - 208 EP - 217 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-35123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Villajos Collado, José Antonio A1 - Jagorel, Noëmie A1 - Reinsch, Stefan T1 - Increasing Exposed Metal Site Accessibility in a Co-MOF-74 Material With Induced Structure-Defects N2 - Metal-organic frameworks (MOFs) are promising nanoporous materials with many practical applications. This owes largely to their remarkable porosity and the presence of specific chemical functionalities, such as exposed metal sites (EMS). The MOF-74 structure is known for exhibiting one of the highest EMS densities among porous materials. Moreover, the inclusion of structural defects has been proposed to enhance activity further. This was previously achieved by mixing the original linker together with a second one, having lower topology. The presence of structural defects was evidenced by the resulting crystalline properties and thermal stability. In this work, different mixtures of tetratopic 2,5-dihydroxyterephthalic acid with up to 60% of the tritopic hydroxyterephtalic acid were used to synthesize crystalline Co-MOF-74-like materials. Materials synthesized from higher proportions than 30% of hydroxyterephtalic acid in the synthesis media collapse upon partial removal of the solvent molecules. This indicates the presence of structural defects and the importance of the solvent molecules in stabilizing the crystalline structures. Electron microscope images show that crystal size reduces with inclusion of hydroxyterephtalic acid as the second linker. The presence of coordinated solvent molecules at the EMS was evaluated by Fourier-transform infrared spectra (FTIR) spectroscopy, so that a higher degree of solvent-exchange was observed during washing for defective structures. Furthermore, TG analysis suggests defective structures exhibit lower desolvation temperatures than the defect-free structures. Finally, N2 adsorption-desorption analyses at −196°C showed an enhanced accessibility of the gas to the inner porosity of the defective structures and therefore, the EMS of the material. All these finding make this pathway interesting to enhance the potential interest of these materials for an industrial application because of both a facilitated activation and a better access to the active sites. KW - MOF-74 KW - Structural defects KW - Mixed-linkers KW - Exposed metal sites KW - Facilitated activation PY - 2019 U6 - https://doi.org/10.3389/fmats.2019.00230 VL - 6 SP - 230 PB - Frontiers Media CY - Lausanne AN - OPUS4-49256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Glass N2 - Überblick über die Arbeitsschwerpunkte des Fachbereichs 5.6 Glas und die Vielfalt des Werkstoffs Glas. An Hand der Vakuumheißgasextraktion (VHE) werden einige Beispiele u.a. zur Bestimmung des Wassergehalts oder des Diffusionskoeffizienten von Wasserstoff in Gläsern gezeigt. Zum Schluss erfolgt ein Ausblick auf die im nächsten Jahr zur Verfügung stehende robotergestützte Glasscreening Anlage. N2 - Overview about the key activities of division 5.6 glass and the diversity of the material glass. For the vacuum hot extraction method (VHE-MS) some examples are presented e. g. for the measurement of water content or the determination of diffusion coefficient of hydrogen in glasses. Finally, an outlook is shown on the robot controlled glass screening device which will be available next year. T2 - BAM - IFW Workshop CY - Berlin, Germany DA - 25.11.2019 KW - Glass KW - Glass screening device KW - Vacuum hot extraction PY - 2019 AN - OPUS4-50452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Welter, T. A1 - Marzok, Ulrich A1 - Deubener, J. A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Hydrogen diffusivity in sodium aluminosilicate glasses N2 - Hydrogen gas diffusivity of fourteen glasses of the Na2O-Al2O3-SiO2 system are studied along the joins quartzalbite-jadeite-nepheline (Qz-Ab-Jd-Np, fully polymerized) and albite-sodium disilicate (Ab-Ds, depolymerized). Density measurements show that ionic porosity decreases from 54.4% (Qz) to 51.5% (Np) and from 52.4% (Ab) to 50.2% (Ds). Hydrogen diffusivity D follows similar trends but at another scale. D at 523 K decreases from 4×10−12 to 3×10−14m2 s−1 (Qz-Np) and from 4×10−13 to 3×10−15m2 s−1 (Ab-Ds). Charge compensating Na+ acting as a filling agent in fully polymerized network structures leads to up to one order of Magnitude higher diffusivities as depolymerized glass structures of the same SiO2 content where Na+ takes the role of a modifier ion. Temperature dependence of the diffusivity indicates that both the activation energy involved with the moving H2 molecule as well as the accessible volume in the structure contribute to this compositional trend. KW - Aluminosilicate glasses KW - Hydrogen diffusivity KW - Ionic porosity PY - 2019 U6 - https://doi.org/10.1016/j.jnoncrysol.2019.119502 VL - 521 SP - 119502 PB - Elsevier B.V. AN - OPUS4-50392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balzer, R. A1 - Behrens, H. A1 - Schuth, S. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Fechtelkord, M. A1 - Deubener, J. T1 - The influence of H2O and SiO2 on the structure of silicoborate glasses N2 - To understand the impact of dissolved water on structure and properties, four boron-rich glasses of molar compositions 15-x Na2O x CaO 15 SiO2 70 B2O3 (with x=0, 7.5, 10) and 10 Na2O 15 SiO2 75 B2O3 were prepared and subsequently hydrated (up to 8 wt% H2O). Density measurements show a non-linear trend upon hydration implying large structural changes in particular at water contents<2 wt%. Near-infrared spectroscopy shows hydroxyl groups are the dominant species in all glasses upon the entire range of water content. Molecular H2O is detectable only at total water contents>2 wt%. 11B MAS NMR spectra show that the abundance of BO4 species is mainly controlled by ratio of (Na2O+CaO)/B2O3 while incorporation of water plays a minor role. Compared to borate glasses, the efficiency of formation of BO4 tetrahedra is favored by crosslinking of the network by SiO4-units. The glass transition temperatures, determined by differential thermal analysis, decreases continuously with water content due to breakage of B-O-B bonds by hydrolysis. However, compared to Silicates and aluminosilicates, the effect of dissolved water is less pronounced which can be explained by weaker B-O-B bonds in comparison to Si-O-Si bonds. KW - High pressure KW - Water speciation KW - Silicoborate glasses KW - Infrared spectroscopy KW - NMR spectroscopy PY - 2019 U6 - https://doi.org/10.1016/j.jnoncrysol.2019.05.030 VL - 519 SP - 38 EP - 51 PB - Elsevier B.V. AN - OPUS4-48748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kiefer, P. A1 - Balzer, R. A1 - Deubener, J. A1 - Behrens, H. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Density, elastic constants and indentation hardness of hydrous soda-lime silica glasses N2 - The effect of structural water on density, elastic constants and microhardness of water-bearing soda-lime-silica glasses of up to 21.5 mol% total water is studied. It is found that the Poisson ratio and the water content are positively correlated, while density and the elastic moduli decrease with increasing water content. Vickers hardness decreases by approximately 27% from the dry to the most hydrous glass. For water fractions <3 mol%, the dependencies are non-linear reflecting the non-linear change in the concentrations of OH and H2O molecules dissolved, whereas for water fractions >3 mol% linear dependencies are found. To distinguish the effect of structural water and environmental water, indentations were performed in toluene, nitrogen gas and air. Timedependent softening was evident for testing dry glasses in humid atmospheres as well as for tests of hydrous glasses in dry atmospheres. This indicates that the response times of dissolved water species are effectively equal in both scenarios. KW - Elastic constants KW - Soda-lime-silica KW - Glass KW - Water content KW - Microhardness PY - 2019 U6 - https://doi.org/10.1016/j.jnoncrysol.2019.119480 SN - 0022-3093 SN - 1873-4812 VL - 521 SP - 119480 PB - Elsevier B.V. AN - OPUS4-48758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Wachtendorf, Volker A1 - Elert, Anna Maria A1 - Falkenhagen, Jana A1 - Becker, Roland A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Tschiche, Harald A1 - Reinsch, Stefan A1 - Weidner, Steffen ED - Scholz, Philipp T1 - Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions N2 - Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography (SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands. KW - Polyurethane KW - Artificial weathering KW - Moisture KW - Crosslinking KW - Degradation PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S0142941819303708 U6 - https://doi.org/10.1016/j.polymertesting.2019.105996 SN - 0142-9418 VL - 78 SP - 105996, 1 EP - 9 PB - Elsevier CY - Amsterdam AN - OPUS4-48625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Welter, T. A1 - Müller, Ralf A1 - Deubener, J. A1 - Marzok, Ulrich A1 - Reinsch, Stefan T1 - Hydrogen Permeation Through Glass N2 - Physical storage of gaseous hydrogen under high-pressure in glassy micro-containers such as spheres and capillaries is a promising concept for enhancing safety and the volumetric capacity of mobile hydrogen storage systems. As very low permeation through the container wall is required for storage of compressed hydrogen, development of glasses of minimal hydrogen permeability is needed. For this purpose, one has to understand better the dependence of hydrogen permeability on glass structure. The paper points out that minimizing the accessible free volume is as one strategy to minimize hydrogen permeability. Based on previously measured and comprehensive literature data, it is shown that permeation is independently controlled by ionic porosity and network modifier content. Thus, ionic porosity in modified and fully polymerized networks can be decreased equally to the lowest hydrogen permeability among the glasses under study. Applying this concept, a drop of up to 30,000 with respect to the permeation of hydrogen molecules through silica glass is attainable. KW - Ionic porosity KW - hydrogen storage KW - Glass KW - Permeability KW - Solubility KW - Diffusivity PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-513927 VL - 6 SP - Article 342 AN - OPUS4-51392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Akatsuka, C. A1 - Honma, T. A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Tanaka, S. A1 - Komatsu, T. T1 - Surface crystallization and gas bubble formation during conventional heat treatment in Na2MnP2O7 glass N2 - The crystallization behavior of sodium ion conductive Na2MnP2O7 glass was examined to clarify the crystallization mechanism. The formation of thermodynamically metastable phase, layered Na2MnP2O7, at the surface of the glass occurred. Heat treatment at 430 °C for 3 h lead to surface crystals of Na2MnP2O7 oriented with the (101) direction perpendicular to the sample surface. As the heat treatment temperature increased, the glass-ceramic samples deformed, and the presence numerous micro bubbles due to dissolved water was detected. KW - Glass-ceramic KW - Crystallization KW - Sodium ion batteries KW - Bubble formation KW - Phosphate PY - 2019 U6 - https://doi.org/10.1016/j.jnoncrysol.2019.01.030 VL - 510 SP - 36 EP - 41 PB - Elsevier B.V. AN - OPUS4-49618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Kiefer, P. A1 - Deubener, J. A1 - Bauer, Ute A1 - Balzer, P. A1 - Behrens, H. T1 - Sub-Tg Relaxation in wasserhaltigen Kalk-Natron-Silikat und Natrium-Borosilikat-Gläsern N2 - Wasser hat einen starken Einfluss auf die Depolymerisation des Glasnetzwerks silikatischer Gläser, was sich durch eine deutliche Senkung der Glasübergangstemperatur, Tg, bemerkbar macht. So hat Wasser einen großen Einfluss auf die Alterung, Ermüdung und das unterkritische Risswachstum in Gläsern. Sub-Tg Relaxationsphänomene spielen hier ebenfalls eine große Rolle, sind aber für Gläser mit hohen Gehalten an strukturell gebundenem Wasser kaum untersucht. In dieser Arbeit wurden daher Kalk-Natron-Silikat (NCS) und Natrium-Borosilikat (NBS) Gläser mit Wassergehalten von bis zu 8 Gew.% mittels Differentialthermoanalyse (DTA), Mikropenetration und vor allem dynamisch mechanischer Thermoanalyse (DMTA) zur Charakterisierung netzwerkbedingter Relaxationsmechanismen (alpha-Relaxation) im Bereich des Glasübergangs sowie weiterer schnellerer sub-Tg Relaxationsmechanismen (beta-, gamma-Relaxation) bei tieferen Temperaturen untersucht. Mit Hilfe der IR-Spektroskopie wurde der Gesamtwassergehalt und die Speziation des Wassers als molekulares Wasser oder als OH-Gruppe in den Gläsern bestimmt. Für niedrige Wassergehalte treten zwei sub-Tg Verlustpeaks auf, die der Bewegung von Alkali bei tiefen Temperaturen (gamma-Relaxation) und einer kooperativen Bewegung verschiedener mobiler Spezies unter Beteiligung von OH bei höherer Temperatur (betaOH- Relaxation) zugeordnet werden können. Bei hohen Wassergehalten, bei denen ein messbarer Anteil an molekularem Wasser im Glas vorliegt, ist ein weiterer Verlustpeak zu beobachten, der mit der Bewegung von molekularem Wasser im Glasnetzwerk in Verbindung gebracht werden könnte (betaH2O-Relaxation). T2 - Fachausschuss I der Deutschen Glastechnischen Gesellschaft (DGG) CY - Erlangen, Germany DA - 26.09.2017 KW - Glas KW - Sub-Tg-Relaxation KW - Wasserspeziation KW - Dynamisch mechanischer Thermoanalyse PY - 2017 AN - OPUS4-43307 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Bauer, Ute A1 - Kiefer, P. A1 - Balzer, R. A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Sub-Tg relaxation in hydrous soda-lime-silicate and sodium-borosilicate glasses N2 - Water plays an important role for the depolymerization of silicate glasses which becomes noticeable by a distinct decrease of glass transformation temperature, Tg. Thus, it has a considerable influence on aging and fatigue as well as on sub-critical crack growth in glasses. In this connection also sub-Tg relaxation processes play a major role, but they are poorly investigated in glasses with high contents of structural bonded water. Therefore, soda-lime-silicate and sodium-borosilicate glasses with water contents up to 5 wt.% H2O were investigated by differential thermal analysis and sphere penetration viscometry, as well as internal friction measurements. The latter was applied to study network related relaxation mechanisms (α-relaxation) in the range of glass transition, as well as faster relaxation modes occurring at lower temperatures (β-, γ- relaxation). Total water content and concentrations of H2O molecules (CH2O) and OH groups (COH) in the glasses were determined by infrared spectroscopy. For low water contents two sub-Tg internal friction peaks were observed and assigned to the low-temperature motion of alkali ions (γ-relaxation) and cooperative movements of dissimilar mobile species under participation of OH at higher temperature (βOH relaxation). For large water contents, where significant amounts of molecular water are evident, a low temperature shoulder appears on the β-relaxation peak. This emerging relaxation mode (βH2O relaxation) was assigned to the motions of H2O molecules. T2 - 91. Glastechnische Tagung CY - Weimar, Germany DA - 28.05.2017 KW - Water-bearing glasses KW - Mechanical loss spectroscopy KW - Relaxation PY - 2017 AN - OPUS4-40810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adamczyk, Burkart A1 - Formanek, P. A1 - Meyer, Christian A1 - Krüger, O. A1 - Scharf, Holger A1 - Reinsch, Stefan A1 - Ostermann, Markus A1 - Nofz, Marianne A1 - Jäger, Christian A1 - Adam, Christian A1 - Emmerling, Franziska T1 - Nanocrystalline and stacking-disordered beta-cristobalite AlPO4 chemically stabilized at room temperature: synthesis, physical characterization, and X-ray powder diffraction data N2 - This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical Emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°. KW - Stabilization of high-temperature phase at RT KW - Nanochrystalline AlPO4 KW - Beta-christobalite structure type KW - High-cristobalite form KW - Aluminium phosphate PY - 2017 U6 - https://doi.org/10.1017/S0885715617000537 SN - 1945-7413 SN - 0885-7156 VL - 32 IS - S1 SP - S193 EP - S200 PB - JCPDS-ICDD CY - Cambridge AN - OPUS4-42235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinsch, Stefan A1 - Kemnitz, E. A1 - Emmerling, Franziska T1 - Ca- and Sr- tetrafluoroisophthalates: mechanochemical synthesis, characterization, and ab initio structure determination N2 - New fluorinated coordination polymers were prepared mechanochemically by milling the alkaline earth metal hydroxides MII(OH)2·xH2O (MII: Ca, Sr) with tetrafluoroisophthalic acid (H2mBDC-F4). The structures of [{Ca(mBDC-F4)(H2O)2}·H2O] and [{Sr(mBDC-F4)(H2O)2}·H2O] were determined based on ab initio calculations and their powder X-ray diffraction (PXRD) data. The compounds are isomorphous and crystallize in the orthorhombic space group P212121. The determined structures were validated by using extended X-ray absorption (EXAFS) data. The new materials were thoroughly characterized using elemental analysis, thermal analysis, magic angle spinning NMR, and attenuated total reflection-infrared spectroscopy. Further characterization methods such as BET, dynamic vapor sorption, and scanning electron microscopy imaging were also used. Our investigations indicate that mechanochemistry is an efficient method for preparing such materials. KW - Mechanochemistry KW - In situ KW - XRD KW - Coordination polymers PY - 2017 UR - http://pubs.rsc.org/-/content/articlehtml/2017/dt/c7dt00734e U6 - https://doi.org/10.1039/c7dt00734e VL - 46 IS - 18 SP - 6003 EP - 6012 AN - OPUS4-41516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bauer, Ute A1 - Behrens, H. A1 - Reinsch, Stefan A1 - Morin, E. I. A1 - Stebbins, J. F. T1 - Structural investigation of hydrous sodium borosilicate glasses N2 - The structural properties of a borosilicate glass with nominal 16 mol% Na2O, 10 mol% B2O3 and 74mol% SiO2 and water contents between 0 and 8wt% H2O (0–22 mol% H2O)were investigated with IR, Raman and 11BMAS NMR spectroscopy. In addition to the pronounced OH stretching vibration band of weakly H-bonded species at 3580 cm−1 the MIR spectra show a triplet at 2900, 2350 and 1750 cm−1, similar as observed in water-bearing silicate glasses. These bands are assigned to OH groups and water molecules which are strongly H-bonded, to non-bridging oxygen. Water species contents determined from absorption bands in the NIR at 5200 cm−1 (molecular H2O), 4700 cm−1 (B\\OH), and 4500 cm−1 (Si\\OH) indicate that hydroxyl groups dominate up to ~6 wt% total H2O. Based on the absorption coefficients known from literature for silicate and borate glasses the B\\OH/Si\\OH ratio is estimated to be ≈0.8. As indicated by density, Raman and NMR data the incorporation ofwater has strong structural impacts in particular at low water contents up to 3 wt% H2O. While the nominally dry glasses still contain a significant fraction (12%) of three-fold coordinated boron, almost all boron is four-fold coordinated in hydrous glasses. The increase of band components in the Raman spectra near 900 cm−1 relative to the region N 1050 cm−1 gives evidence for depolymerization of the network upon hydration. Fitting of the spectra with Gaussians implies that silica tetrahedra with two non-bridging oxygen (Q2) are preferentially formed by reactionwithwater on expense of tetrahedra linked to four tetrahedra (Q4). KW - Glass structure KW - Borosilicate glasses KW - Water-bearing glasses KW - Spectroscopy PY - 2017 U6 - https://doi.org/10.1016/j.jnoncrysol.2017.03.023 SN - 0022-3093 SN - 1873-4812 VL - 465 SP - 39 EP - 48 PB - Elsevier B. V. AN - OPUS4-40805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Waurischk, Tina A1 - Müller, Ralf A1 - Arendt, F. A1 - Sierka, M. A1 - Diegeler, A. T1 - A new robot-assisted compositional screening method N2 - The system Na2O.B2O3-SiO2 (NBS) is the basis of many industrial glass applications and therefore one of the most studied systems at all. Glass formation is possible over a wide compositional range, but the system also contains ranges of pronounced phase separation and crystallization tendency. Despite its importance, experimental data are limited to few compositional areas. The general understanding and modelling of glass formation, phase separation, and crystallization in this system would therefore be easier if small step melt series could be studied. The efficient melting of such glass series is now possible with the new robotic glass melting system at the Federal Institute for Materials Research and Testing (BAM, Division Glasses). Using three exemplary joins within this NBS system, the small step changes of glass transition temperature (Tg), crystallization behavior as well as glass density (Roh) was studied. Additionally, experimental Tg and Roh data were compared with their modeled counterparts using SciGlass and a newly developed DFT model, respectively. T2 - Annual meeting of the French Union for Science and Glass Technology (USTV) and the 96th Annual Meeting of the German Society of Glass Technology - USTV-DGG joint meeting. CY - Orléans, France DA - 22.06.2023 KW - Robot-assisted galss melting KW - Sodiumborosilicate glasses KW - Density KW - Glass transformation temperature KW - Property simulation PY - 2023 AN - OPUS4-58724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Welter, T. A1 - Müller, Ralf A1 - Deubener, J. T1 - Hydrogen Permeability of Tectosilicate Glasses for Tank Barrier Liners N2 - The permeation of hydrogen gas was studied in meta-aluminous (tectosilicate) glass powders of Li2O×Al2O3×SiO2 (LAS), Na2O×Al2O3×SiO2 (NAS) and MgO×Al2O3×SiO2 (MAS) systems by pressure loading and vacuum extraction in the temperatures range 210–310 °C. With this method, both the solubility S and the diffusivity D were determined, while the permeability was given by the product SD. For all glasses, S was found to decrease with temperature, while D increased. Since the activation energy of diffusion of H2 molecules exceeded that of dissolution, permeation increased slightly with temperature. When extrapolated to standard conditions (25 °C), the permeability of tectosilicate glasses was found to be only 10-22–10-24 mol H2 (m s Pa)-1, which is 8–10 magnitudes lower than most polymers. Thin glass liners of these compositions are expected to be the most effective barrier for tanks of pressurised hydrogen. KW - Hydrogen permeation KW - Aluminosilicate glasses KW - Hydrogen storage tank KW - Glass liner PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-587284 VL - 1 SP - 1 EP - 11 AN - OPUS4-58728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ivanov, V.V. A1 - Tielemann, Christopher A1 - Avramova, K. A1 - Reinsch, Stefan A1 - Tonchev, V. T1 - Modelling crystallization: When the normal growth velocity depends on the supersaturation N2 - The crystallization proceeds by the advance of the crystal faces into the disordered phase at the expense of the material excess, the supersaturation. Using a conservation constraint for the transformation ratio α∈[0,1] as complementing the rescaled supersaturation to 1 and a kinetic law for the normal growth velocity as function of the supersaturation raised to power g, the growth order, we derive an equation for the rate of transformation dα/dt. We integrate it for the six combinations of the three spatial dimensions D = 1, 2, 3 and the two canonical values of g = 1, 2 towards obtaining expressions for αDg. The same equation, with g = 1 and D = n (n is the so called Avrami exponent) is obtained when taking only the linear in α term from the Taylor’s expansion around α = 0 of the model equation of Johnson-Mehl-Avrami-Kolmogorov (JMAK). We verify our model by fitting datasets of α21 and α31 (from α = 0 to αupper = 0.999) with JMAK to obtain from the fit n = 1.725, 2.43, resp. We show further how the values of n depend on the value of αupper to which the fit is performed starting always from 0. Towards building a validation protocol, we start with validating α21 with published results. KW - Crystallization KW - Supersaturation KW - Growth kinetics KW - Growth rate KW - JMAK model PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-581706 SN - 0022-3697 VL - 181 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-58170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paskin, A. A1 - Couasnon, T. A1 - Perez, J. P. H. A1 - Lobanov, S. S. A1 - Blukis, R. A1 - Reinsch, Stefan A1 - Benning, L. G. T1 - Nucleation and Crystallization of Ferrous Phosphate Hydrate via an Amorphous Intermediate N2 - The fundamental processes of nucleation and crystallization are widely observed in systems relevant to material synthesis and biomineralization; yet most often, their mechanism remains unclear. In this study, we unravel the discrete stages of nucleation and crystallization of Fe3(PO4)2·8H2O (vivianite). We experimentally monitored the formation and transformation from ions to solid products by employing correlated, time-resolved in situ and ex situ approaches. We show that vivianite crystallization occurs in distinct stages via a transient amorphous precursor phase. The metastable amorphous ferrous phosphate (AFEP) intermediate could be isolated and stabilized. We resolved the differences in bonding environments, structure, and symmetric changes of the Fe site during the transformation of AFEP to crystalline vivianite through synchrotron X-ray absorption spectroscopy at the Fe K-edge. This intermediate AFEP phase has a lower water content and less distorted local symmetry, compared to the crystalline end product vivianite. Our combined results indicate that a nonclassical, hydration-induced nucleation and transformation driven by the incorporation and rearrangement of water molecules and ions (Fe2+ and PO4 3−) within the AFEP is the dominating mechanism of vivianite formation at moderately high to low vivianite supersaturations (saturation index ≤ 10.19). We offer fundamental insights into the aqueous, amorphous-to-crystalline transformations in the Fe2+−PO4 system and highlight the different attributes of the AFEP, compared to its crystalline counterpart. KW - Nucleation KW - Crystallization KW - Vivianite KW - Ferrous phosphate hydrate PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-580696 SN - 0002-7863 VL - 145 IS - 28 SP - 15137 EP - 15151 PB - ACS Publications AN - OPUS4-58069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abel, Andreas A1 - Rosalie, Julian M. A1 - Reinsch, Stefan A1 - Zapala, Pawel A1 - Michels, Heiner A1 - Skrotzki, Birgit T1 - Influence of Mo and B additions in intermetallic near-Fe3Al alloys on microstructure and mechanical properties N2 - Iron aluminides, already reported in the late 19th century, did not cease to attract the interest of scientists and engineers ever since. Besides good oxidation resistance, low density and resource availability, potentials for hightemperature strengths that compete with high-alloy steels were unlocked by low alloy contents. Still, research on alloy design continues, as alloying usually comes at the price of brittleness in low-temperature regimes. A potential candidate is the quinary Fe–Al–Mo–Ti–B system which is strengthened by solid solution and eutectic borides. It was shown to have good strength and outstanding creep resistance under compressive loading up to elevated temperatures. Although the individual effect of alloy additions is well understood in iron aluminides, little is known about the combined effects of alloying concentrations on microstructure, phase stability and mechanical properties. Therefore a systematic study of two Ti-doped near-Fe3Al alloys with varying contents of Mo (2–4 at.%) and B (0.5–1 at.%) was conducted. In total eight different alloys were fabricated by investment casting into ceramic shell molds. Alloys were characterized and compared by grain size, phase transitions, microstructure evolution as well as elemental compositions and volume fractions of phases. For mechanical characterization, macrohardness and microhardness tests as well as tensile tests at ambient and high tempera tures were conducted. Independent of alloy additions, alloys with 24–25 at.% Al exhibit superior proof strength due to a higher matrix hardness. Decreasing B content generally decreases strength by lower secondary phase fractions which contribute via particle hardening. Reducing Mo content decreases both the solute concentration in the matrix and secondary phase fractions. Surprisingly, strength is similar or even superior to alloys with higher Mo content. Strength relations are discussed with a focus on solid-solution hardening theory and other competing strengthening mechanisms. KW - Materials Chemistry KW - Metals and Alloys KW - Mechanical Engineering KW - Mechanics of Materials KW - General Chemistry PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-585284 VL - 163 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-58528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, J. A1 - Farris, L. A1 - Nolze, Gert A1 - Reinsch, Stefan A1 - Cios, G. A1 - Tokarski, T. A1 - Thompson, S. T1 - Microstructure evolution in Inconel 718 produced by powder bed fusion additive manufacturing N2 - Inconel 718 is a precipitation strengthened, nickel-based super alloy of interest for the Additive Manufacturing (AM) of low volume, complex parts to reduce production time and cost compared to conventional subtractive processes. The AM process involves repeated rapid melting, solidification and reheating, which exposes the material to non-equilibrium conditions that affect elemental segregation and the subsequent formation of solidification phases, either beneficial or detrimental. These variations are difficult to characterize due to the small length scale within the micron sized melt pool. To understand how the non-equilibrium conditions affect the initial solidification phases and their critical temperatures, a multi-length scale, multi modal approach has been taken to evaluate various methods for identifying the initial phases formed in the as-built Inconel 718 produced by laser-powder bed fusion (L-PBF) additive manufacturing (AM). Using a range of characterization tools from the bulk differential thermal analysis (DTA) and x-ray diffraction (XRD) to spatially resolved images using a variety of electron microscopy tools, a better understanding is obtained of how these minor phases can be properly identified regarding the amount and size, morphology and distribution. Using the most promising characterization techniques for investigation of the as-built specimens, those techniques were used to evaluate the specimens after various heat treatments. During the sequence of heat treatments, the initial as-built dendritic structures recrystallized into well-defined grains whose size was dependent on the temperature. Although the resulting strength was similar in all heat treated specimens, the elongation increased as the grain size was refined due to differences in the precipitated phase distribution and morphology. KW - Metal additive manufacturing KW - Inconel 718 KW - Heat treatment KW - Grain boundary precipitates KW - Laves phase PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-542758 SN - 2504-4494 VL - 6 IS - 1 SP - 1 EP - 20 PB - MDPI CY - Basel AN - OPUS4-54275 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gomes Fernandes, Roger A1 - Al-Mukadam, Raschid A1 - Bornhöft, Hansjörg A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Selle, Susanne A1 - Deubener, Joachim T1 - Viscous Sintering of Acid Leached Glass Powders N2 - The process of viscous flow sintering is a phenomenon that is closely linked to the surface properties of the glass particles. In this work, we studied the extreme case of acid-leaching of soda-lime-silicate glass beads of two different particle size distributions and its effects on non-isothermal viscous sintering of powder compacts. Depth profiling of the chemical composition after leaching revealed a near-surface layer depleted in alkali and alkaline earth ions, associated with concurrent hydration as mass loss was detected by thermogravimetry. Heating microscopy showed that acid treatment of glasses shifted the sinter curves to higher temperatures with increasing leaching time. Modelling of the shrinkage with the cluster model predicted a higher viscosity of the altered surface layer, while analysis of the time scales of mass transport of mobile species (Na+, Ca2+ and H2O) during isochronous sintering revealed that diffusion of Na+ can compensate for concentration gradients before sintering begins. Also, exchanged water species can diffuse out of the altered layer, but the depletion of Ca2+ in the altered surface layer persists during the sinter interval, resulting in a glass with higher viscosity, which causes sintering to slow down. KW - Glass powder KW - Viscous sintering KW - Acid-leaching KW - Sinter retardation PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-589008 VL - 1 SP - 37 EP - 53 AN - OPUS4-58900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Böcker, Wolfgang D. G. A1 - Bücker, Michael A1 - Seeger, Stefan A1 - Unger, Brita T1 - Development of wood-inorganic composites with enhanced properties and environmental stability T2 - 4th International Wood and Natural Fibre Composites Symposium CY - Kassel, Germany DA - 2002-04-10 PY - 2002 AN - OPUS4-12336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -