TY - JOUR A1 - Stoesser, R. A1 - Steinfeldt, N. A1 - Brenneis, Rudolf A1 - Nofz, Marianne T1 - Electron spin resonance in situ observation of the bending stress process in corundum materials and glasses KW - Elektronenspinresonanz KW - Beugung KW - Korund KW - Glas PY - 1996 SN - 0022-2461 SN - 1573-4803 VL - 31 SP - 1405 EP - 1413 PB - Springer Science + Business Media B.V. CY - Norwell, Mass. AN - OPUS4-662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mosel, Günter A1 - Nofz, Marianne T1 - Zn-K EXAFS investigations of zinc aluminosilicate glasses and ZnO-doped calcium aluminosilicate glasses KW - Zink KW - Glas PY - 1995 SP - 615 PB - Hamburger Synchrotronstrahlungslabor CY - Hamburg AN - OPUS4-600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartoll, Jens A1 - Nofz, Marianne A1 - Stößer, R. T1 - Generation and conversion of electronic defects in calcium carbonates by UV/Vis light N2 - Radical species like CO-2,CO-3, SO-2, and SO-3 can be created by exposing natural and synthetic calcium carbonates to sunlight or to the light of a Hg(Xe) lamp. This poses as a risk for ESR dating of these materials, because the radicals formed by light exposure cannot be distinguished from those generated by radioactivity. Furthermore, paramagnetic centers like SO-2, electrons trapped near Zn2+ or Cd2+ ions, surface defects, and radicals with g?=2.0040, can be bleached in ?-irradiated samples by light and show conversion effects. KW - ESR PY - 2000 U6 - https://doi.org/10.1016/S0969-8043(00)00044-0 SN - 0883-2889 SN - 0969-8043 IS - 52 SP - 1099 EP - 1105 PB - Elsevier CY - Amsterdam AN - OPUS4-892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Bartoll, Jens A1 - Stößer, R. T1 - Complementarity of ESR and optical absorption of gamma-irrradiated silicate glasses N2 - Radiation defects in alkaline earth silicate glasses are studied by means of ESR and optical spectroscopies. Previously undiscovered relations between findings of both methods are deduced using four different experimental tools: (i) variation of chemical glass composition; (ii) isochronal annealing of ggr-irradiated samples; (iii) optical bleaching of ggr-irradiated samples; (iv) variation of the ggr-dose. Oxygen hole centres are mainly responsible for the radiation induced absorption in the visible part of the optical spectrum. Previously undescribed electron centres with broad and asymmetric ESR resonances (gprime=1·955) contribute to the optical spectra (200–2000 nm) in a small way. It is suggested they are electrons trapped on small aggregates of alkaline earth ions. The radiation induced recharging of incorporated Fe3+ ions is also evidenced by optical and ESR spectroscopies. Fe3+ ions react as electron traps forming not only Fe2+ but also {Fe3+}- species which might be responsible for an absorption band at 300 nm. A correlation was found between the changes of intensity with those of the ESR spectroscopically detected Fe3+ content of the samples. PY - 2000 UR - http://www.ingentaconnect.com/content/sgt/pcg/2000/00000041/00000003/4103140 SN - 0031-9090 VL - 41 IS - 3 SP - 140 EP - 149 PB - Thornton CY - Sheffield AN - OPUS4-938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Stösser, R. T1 - Generation and stimulated decay of paramagnetic centres in laser excited glasses N2 - Direct coupling of an excimer laser to the cavity of an X-band ESR spectrometer enabled in situ observation of ultraviolet irradiation (248 nm) induced effects in aluminosilicate glasses. Under these conditions the radiation was absorbed by iron traces present in the glasses and finally electron/hole pairs were formed. The trapping and detrapping of electrons and holes, e.g. generation and decay of paramagnetic defects, could be followed in dependence on repetition rate of the laser (1–20 Hz), temperature during irradiations (4·2–300 K) and composition of the glasses. The holes were trapped at Si–O and Al–O–Si sites. Zn2+ and Cd2+ ions (likely as parts of Zn–O or Cd–O aggregates) as well as Fe3+ ions served as effective electron traps. Additionally, changes of the dielectric properties of the samples during and after ultraviolet irradiations could be monitored directly. These are large if relatively mobile ions (e.g. Na+) are present in the sample. Comparison of ultraviolet to -irradiated samples shows that the type of traps present in the samples mainly depends on the glass composition. However, the relative amounts of stabilised holes and electrons essentially depend on the conditions and parameters of irradiation. PY - 2001 UR - http://www.ingentaconnect.com/content/sgt/pcg/2001/00000042/00000006/4206401 SN - 0031-9090 VL - 42 IS - 6 SP - 401 EP - 407 PB - Thornton CY - Sheffield AN - OPUS4-1329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hübert, Thomas A1 - Mosel, Günter A1 - Nofz, Marianne T1 - Local order of V5+Ions in borate glasses investigated by EXAFS N2 - Glasses in the systems Li2O–B2O3–V2O5 and ZnO–B2O3–V2O5 as well as crystalline reference substances were investigated by V-K-EXAFS. The glasses have a high modifier content ([Li2O, ZnO]/[B2O3] ratio>1) and contain 10–50 mol% V2O5. The V–O interatomic distance, coordination number and Debye–Waller factor were determined from the analysis of the measured absorption spectra. In the glasses investigated (and in binary lithium or zinc vanadate glasses too) VO4 tetrahedra are the predominant coordination polyhedra for the vanadium ions. The symmetry of the tetrahedra is more or less distorted in comparison to crystalline substances. The VO4 tetrahedra can be either directly connected to each other or incorporated into borate BO3/BO4 groupings. Structural elements which are comparable to those in crystalline substances can be discussed. In glasses of the metaborate composition, vanadium can be incorporated in chain or ring [BØ2O-]n metaborate groupings. With increasing V2O5 content the vanadium ions can extensively replace boron ions and form distorted tetrahedra in VØ2O2- metavanadate groups. In glasses of high modifier content and low vanadium amount the vanadium ions create nearly regular tetrahedra of isolated VO43- ortho- or V2ØO64- pyrovanadate groups in the presence of B2ØO44- pyroborate, BO33- orthoborate and BØ4- groups. T2 - Third International Conference on borate Glasses, Crystals and Melts CY - Sofia, Bulgaria DA - 1999-07-04 PY - 2000 UR - http://www.ingentaconnect.com/content/sgt/pcg/2000/00000041/00000005/4105300 SN - 0031-9090 VL - 41 IS - 5 SP - 300 EP - 303 PB - Thornton CY - Sheffield AN - OPUS4-3769 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzaré, J.Y. A1 - Silly, G. A1 - Klein, J. A1 - Scholz, G. A1 - Stösser, R. A1 - Nofz, Marianne T1 - Electron paramagnetic resonance investigations of alpha-Al2O3 powders doped with Fe3+ ions: experiments and simulations N2 - Electron paramagnetic resonance (EPR) of Fe3+ ions in Al2O3 is studied in powder samples prepared by different routes and/or modified by thermal or mechanical treatments, with different doping levels and grain sizes. The measurements are performed in various frequency bands (S, X, K, Q and W) and with bimodal detection in X-band. Simulations of the spectra are achieved with a code designed for computing EPR powder spectra described by any spin Hamiltonian including second-, fourth-and sixth-order ZFS terms (S ? 7/2). The linewidths, intensities and lineshapes are accounted for. The lineshape is Gaussian at low Fe3+ concentration whereas it is Lorentzian for higher concentration. The linewidths are interpreted as the superimposition of three main contributions: intrinsic linewidth, dipolar broadening and broadening due to lattice imperfections. The latter is tentatively interpreted in terms of quadrupolar spin Hamiltonian parameter distributions treated using first-order perturbation theory. Whatever the sample, only the b22 spin Hamiltonian parameter is found to be distributed around a mean zero value which corresponds to rhombic distortions. Angle and bond length distributions are tentatively extracted from the b22 distributions which gives some insight into the local order around the spin probe in relation to the preparation and treatment of the samples. PY - 2002 U6 - https://doi.org/10.1088/0953-8984/14/43/329 SN - 0953-8984 SN - 1361-648X VL - 14 SP - 10331 EP - 10348 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-2261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peuker, Christel A1 - Brzezinka, Klaus-Werner A1 - Nofz, Marianne A1 - Geißler, Heinz T1 - IR and Raman spectroscopic study of some strontium aluminosilicate glasses PY - 2003 SN - 0927-4472 VL - 76 IS - 6 SP - 276 EP - 284 PB - Elsevier CY - Amsterdam AN - OPUS4-3028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altantsog, Pagvajav A1 - Ojunbileg, L. A1 - Tserenshimed, M. A1 - Chadraabal, Shgdariin A1 - Müller, Ralf A1 - Nofz, Marianne A1 - Gaber, Martin A1 - Batdemberel, G. A1 - Sangaa, D. T1 - Some experimental results of glass melting by using sands from Buir nuur PY - 2002 VL - 1 SP - 103 EP - 118 AN - OPUS4-3113 LA - mon AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altantsog, Pagvajav A1 - Ojunbileg, L. A1 - Palam, B. A1 - Tserenshimed, M. A1 - Chadraabal, Shgdariin A1 - Müller, Ralf A1 - Nofz, Marianne A1 - Gaber, Martin T1 - Some experimental results of glass melting by using sands from Buir nuur N2 - We have carried out some laboratory experiments to establish possibilities to melt 16Na2O*10CaO*74SiO2 glasses from consisting of mainly quarz sands of Buir nuur lake. When the sands used directly, the formed glasses had slight blue colour, the origin of which may be connected with aluminium and iron impurities in the sands. Presence of these impurities is confirmed by chemical analyse and ESR study data. Allso have been studied liquid gas extraction phenomena in the sands and melted glass samples and determined some physical properties of them. PY - 2002 VL - 17 SP - 107 EP - 115 AN - OPUS4-3118 LA - mon AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübert, Thomas A1 - Mosel, Günter A1 - Nofz, Marianne T1 - Anwendung der Röntgenabsorptionsspektroskopie (XAFS) in der Glasstrukturforschung T2 - 71. Glastechnische Tagung CY - Bayreuth, Deutschland DA - 1997-05-26 PY - 1997 SP - 77 EP - 80 CY - Frankfurt/Main AN - OPUS4-3773 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Reich, Christian A1 - Stößer, R. A1 - Bartoll, Jens A1 - Janata, E. T1 - On the interaction of glasses with high-energy radiation - Combined ESR and optical studies T2 - 71st Annual Meeting of the German Society of Glass Technology (DGG) CY - Bayreuth, Germany DA - 1997-05-01 KW - Glas KW - Glaskeramik KW - Optical spectroscopy PY - 1999 SN - 0946-7475 VL - 72 IS - 3 SP - 76 EP - 90 PB - Verl. d. Dt. Glastechn. Ges. CY - Offenbach AN - OPUS4-758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Stößer, R. A1 - Sebastian, S. A1 - Scholz, G. A1 - Willer, M. A1 - Jeschke, G. A1 - Schweiger, A. T1 - Pulse EPR Spectroscopy of Cu2+ - Doped Inorganic Glasses KW - EPR Spectroscopy KW - Inorganic glasses PY - 1999 SN - 0937-9347 SN - 1613-7507 IS - 16 SP - 507 EP - 528 PB - Springer CY - Wien AN - OPUS4-760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kautek, Wolfgang A1 - Rudolph, Pascale A1 - Nofz, Marianne T1 - ESR-Untersuchungen von Barium-Alumo-Borosilikatglas nach Wechselwirkung mit Ultrakurzpuls-Laserstrahlung T2 - Bunsentagung 2002 ; Industrie-Symposium Industrielle Anwendungen der NMR: Struktur und Dynamik ; 101. Hauptversammlung der Deutschen Bunsen-Gesellschaft für Physikalische Chemie CY - Potsdam, Germany DA - 2002-05-09 PY - 2002 IS - 101 SP - 1(?) CY - Potsdam AN - OPUS4-1587 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 - CONF A1 - Nofz, Marianne A1 - Stößer, R. A1 - Hübert, Thomas A1 - Sebastian, S. T1 - Defect trapping in glassy-crystalline sensor materials T2 - VIIIth International Conference on the Physics of Non-Cryst. Solids CY - Turku, Finland DA - 1995-06-28 PY - 1995 AN - OPUS4-6545 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 AN - OPUS4-7402 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Stösser, R. A1 - Scholz, G. A1 - Dörfel, Ilona A1 - Schultze, Dietrich T1 - The thermally induced transformation of pseudoboehmite gels - a comparison of the effects of corundum seeding and iron doping N2 - The transformation of doped or seeded pseudoboehmite to corundum was studied by combining thermal analysis, X-ray diffraction, transmission electron microscopy, and electron paramagnetic resonance spectroscopy. The temperature of phase transformation to corundum was lowered by about 130 °C when Fe3+ or corundum seeds were added to the sols. Action of Fe3+ ions depends on the actual degree of thermally induced transformation of pseudoboehmite via transition aluminas to corundum and the ability of these alumina phases to incorporate Fe3+ ions. These ions tend to aggregate with increasing iron concentration of the alumina phases and can work as nucleation centers. Small (not, vert, similar20 nm) corundum particles act as active nucleation sites whereas larger grains (200–400 nm) also present in the samples are less effective. For the first time trapping and stabilization of NO2 molecules in transition aluminas formed by a sol–gel route was shown. KW - Grain size KW - Sol-gel processes KW - Electron microscopy KW - X-ray methods KW - Al2O3 PY - 2005 U6 - https://doi.org/10.1016/j.jeurceramsoc.2004.04.014 SN - 0955-2219 SN - 1873-619X VL - 25 IS - 7 SP - 1095 EP - 1107 PB - Elsevier CY - Oxford AN - OPUS4-7455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Dreßler, Martin A1 - Unger, Brita A1 - Reinsch, Stefan A1 - Dörfel, Ilona T1 - Alumosole zur Schichtherstellung T2 - 80. Glastechnische Tagung CY - Dresden, Germany DA - 2006-06-12 PY - 2006 AN - OPUS4-12490 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stösser, R. A1 - Scholz, G. A1 - Buzaré, J.-Y. A1 - Silly, G. A1 - Nofz, Marianne A1 - Schultze, Dietrich T1 - A magnetic resonance investigation of the process of corundum formation starting from sol-gel precursors PY - 2005 SN - 0002-7820 SN - 1551-2916 VL - 88 IS - 10 SP - 2913 EP - 2922 PB - Blackwell Publishing CY - Malden AN - OPUS4-11888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Nofz, Marianne A1 - Feist, M. A1 - Scholz, G. T1 - Fe3+-assisted formation of alpha-Al2O3, starting from sol-gel precursors N2 - The role of Fe3+ ions in the transformations from boehmites and pseudoboehmite xerogels via transition aluminas to corundum was studied here. Especially, the active iron species responsible for the decrease of the temperature of transformation to corundum were looked for. To enable the formation of various Fe3+ and Fe2+ species, samples were subjected to thermal treatments in different atmospheres as well as mechanically activated. Thermal analysis and ESR spectroscopy served to follow the processes and to characterise the resulting products. It was found that (i) isolated Fe3+ ions can indicate local structural changes but have (almost) no influence on the temperature of corundum formation, (ii) the temperature of corundum formation decreases in the result of action of small α-Fe2O3 particles and (iii) during thermal treatments Fe3+ ions are distributed between different phases or precursors thereof: transition aluminas, corundum, Fe2O3, and a Fe3+ pool. KW - Redox process KW - ESR spectroscopy KW - Thermal analysis KW - Sol-gel process KW - Boehmite KW - Corundum PY - 2006 U6 - https://doi.org/10.1016/j.jssc.2005.11.026 SN - 0022-4596 SN - 1095-726X VL - 179 IS - 3 SP - 645 EP - 657 PB - Elsevier CY - San Diego, Calif. AN - OPUS4-11889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Stösser, R. A1 - Scholz, G. A1 - Buzaré, J.Y. A1 - Silly, G. A1 - Schulze, Dietmar T1 - A magnetic resonance investigation of the process of corundum formation strating from sol-gel precursors T2 - Congress Ampere CY - Lille, France DA - 2004-09-06 PY - 2004 AN - OPUS4-5625 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 T1 - Alumina based thin layers containing corundum T2 - 15. Symposium: Verbundwerkstoffe und Werkstoffverbunde CY - Kassel, Germany DA - 2004-04-06 PY - 2004 AN - OPUS4-5618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Unger, Brita A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Dreßler, Martin A1 - Sojref, Regine A1 - Reinsch, Stefan A1 - Schulze, Dietmar A1 - Dörfel, Ilona T1 - Struktur und thermische Eigenschaften von Böhmit- und Alumo-Xerogelen T2 - XXV. Tagung des AK "Nichtkristalline und partiellkristalline Strukturen" der DKG CY - Wolfersdorf, Germany DA - 2004-09-27 PY - 2004 AN - OPUS4-5632 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Schulze, Dietmar A1 - Reinsch, Stefan A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Scholz, G. T1 - Thermische Zersetzung von Böhmit- und amorphen Alumo-Xerogelen T2 - Jahrestagung der Gesellschaft für thermische Analyse (GEFTA) CY - Braunschweig, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-5633 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mosel, Günter A1 - Nofz, Marianne A1 - Hübert, Thomas T1 - O-K EXAFS studies of the local order of oxygen ions in crystalline and glassy materials PY - 1997 SN - 0179-4159 SP - 198 EP - 200 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mosel, Günter A1 - Nofz, Marianne A1 - Hübert, Thomas A1 - Brenneis, Rudolf A1 - Köcher, Peter A1 - Kley, Gerd T1 - Zn-K EXAFS investigations on ZnO/ZnS-containing vitrified incinerator ashes PY - 1998 SP - 833 EP - 834 PB - Hamburger Synchrotonstrahlungslabor CY - Hamburg AN - OPUS4-7033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mosel, Günter A1 - Nofz, Marianne A1 - Lange, Dörte A1 - Hübert, Thomas T1 - The local environment of vanadium ions in glasses of the system ZnO-B2O3-V2O5 investigated by V-K EXAFS spectroscopy PY - 1996 SP - 749 EP - 750 PB - Hamburger Synchrotonstrahlungslabor CY - Hamburg AN - OPUS4-7034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mosel, Günter A1 - Nofz, Marianne A1 - Hübert, Thomas T1 - An EXAFS investigation of the local order of Fe2+ and Fe3+ ions in a silicate glass at low Fe concentrations PY - 1997 SP - 743 EP - 744 PB - Hamburger Synchrotonstrahlungslabor CY - Hamburg AN - OPUS4-7035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Schulz, Wencke A1 - Sojref, Regine A1 - Dörfel, Ilona A1 - Feigl, Michael T1 - Preparation and barrier properties of sol-gel alumina coatings on high temperature alloys T2 - Particoat CY - Costa Teguise, Spain DA - 2012-10-15 PY - 2012 AN - OPUS4-27445 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Dreßler, Martin A1 - Feigl, Michael A1 - Schulz, Wencke A1 - Sojref, Regine T1 - Preparation and properties of sol-gel alumina coatings on metals for high temperature applications T2 - 10th CMCee CY - Dresden, Germany DA - 2012-05-20 PY - 2012 AN - OPUS4-27446 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Corrosion of uncoated and alumina coated steel X20CrMoV12-1 in H2O-CO2-O2 and air at 600 °C N2 - Future coal power plants will in case of oxyfuel combustion be operated with altered atmospheres. Hence, corrosion attack might become more severe and steels have to be protected. An alumina-sol was used to coat X20CrMoV12-1 (X20) with alumina to test the protection. Testing was performed at 600 °C in flowing H2O–CO2–O2 and static laboratory air for 1000 h. Oxidation under air is minor compared to exposure in oxyfuel atmosphere. In both cases a multilayered oxide (hematite, magnetite, spinel) was formed on uncoated steels. Carburization appeared on uncoated X20 in H2O–CO2–O2. The coating demonstrates a high protection. KW - A. Steel KW - B. SEM KW - B. STEM KW - C. Carburization KW - C. High temperature corrosion KW - C. Oxide coatings PY - 2013 U6 - https://doi.org/10.1016/j.corsci.2012.10.031 SN - 0010-938X VL - 68 SP - 44 EP - 50 PB - Elsevier Ltd. CY - Orlando, Fla. AN - OPUS4-27636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine T1 - Microstructure of sol-gel derived corundum containing coatings N2 - Up to ~ 3 µm thick alumina coatings on corundum ceramic, soda–lime–silica glass and Inconel718™ were produced from mixtures of boehmite sols and corundum suspensions. Transmission electron micrographs in combination with electron diffraction and energy dispersive X-ray spectroscopy served to identify crystallographic phases and to characterize the microstructure of the coatings. Using corundum ceramic as substrate the initially deposited boehmite transforms via transition aluminas to corundum while heating to 1200 °C. In the cases of glass and Inconel718™ thermal treatments up to 520 °C and 1100 °C, respectively, cause diffusion of ions from the substrates into the coatings. Thus additional oxide phases were formed. All coatings are free of cracks or delaminations and do not show any directed crystal growth. KW - Aluminium oxide KW - Coatings KW - Ceramics KW - Transmission electron microscopy KW - TEM KW - Sol-gel KW - Corundum KW - Alumina PY - 2007 SN - 0040-6090 VL - 515 IS - 18 SP - 7145 EP - 7154 PB - Elsevier CY - Amsterdam AN - OPUS4-15016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Saliwan Neumann, Romeo A1 - Dörfel, Ilona A1 - Griepentrog, Michael T1 - Sol-gel derived alumina layers on nickel-base superalloy Inconel-718 (IN-718) N2 - Modified Yoldas sols can be used to prepare crack-free well adherent layers on different substrate materials such as soda–lime glass, corundum and metal (IN-718). These layers having thicknesses of 0.6 µm are strain tolerant and withstand thermal cycling between 810 °C and room temperature. Introducing alpha-Al2O3 filler particles into modified Yoldas sols allows the preparation of thicker layers of 1.6 µm, which as well can be thermally cycled without noticeable delaminations. Chemical bonding seems to be the predominant layer bonding mechanism. KW - Sol-gel KW - Alumosol KW - Filler particles KW - Inconel-718 KW - Scanning electron microscopy PY - 2008 U6 - https://doi.org/10.1016/j.tsf.2008.08.124 SN - 0040-6090 VL - 517 IS - 2 SP - 786 EP - 792 PB - Elsevier CY - Amsterdam AN - OPUS4-18263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Mücke, Udo T1 - Partiell korundhaltige Aluminiumoxid-Schichten auf Glas T2 - 77. Glastechnische Tagung CY - Leipzig, Germany DA - 2003-05-26 PY - 2003 AN - OPUS4-4752 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Dreßler, Martin A1 - Sojref, Regine A1 - Reinsch, Stefan A1 - Pauli, Jutta A1 - Malz, Frank A1 - Jäger, Christian A1 - Dörfel, Ilona T1 - Al-Speciation in wässrigen Beschichtungssolen und Konsequenzen für das Phasentransformationsverhalten der resultierenden festen Produkte T2 - Sitzung des Fachausschuß I "Physik und Chemie des Glases" der Deutschen Glastechnischen Gesellschaft (DGG) CY - Ilmenau, Germany DA - 2007-03-22 PY - 2007 AN - OPUS4-15491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dörfel, Ilona T1 - High-temperature resistant alumina coatings on Ni-base alloys T2 - EUROMAT 2007 CY - Nuremberg, Germany DA - 2007-09-10 PY - 2007 AN - OPUS4-15492 LA - deu 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 - CONF A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Dreßler, Martin T1 - A TEM study of sol-gel alumina coatings on Ni-base superalloys T2 - First Japanese-German Workshop on: Properties and Performance of Thermal Barrier Coatings and Factors Affecting it CY - Darmstadt, Germany DA - 2006-09-13 PY - 2006 AN - OPUS4-14244 LA - eng 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 - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Gemeinert, Marion T1 - Rheology, UV-vis transparency and particle size of modified Yoldas sols N2 - Alumina sols were prepared using a modified Yoldas procedure, thus resulting in sols with high solids content, excellent long term stability and small particle size. PH-value ranged between 3.7 and 0.6. Sols were characterised using rheological, UV-vis transmission and particle size measurements. Depending on NO3-/Al molar ratio as well as solids content, sols vary. Analysis of reduced viscosities indicate the formation of chainlike polymeric species above a critical solids fraction. KW - Alumo-sol KW - Rheology KW - UV-vis-transparency PY - 2006 U6 - https://doi.org/10.1007/s10971-006-6634-5 SN - 0928-0707 SN - 1573-4846 VL - 38 IS - 3 SP - 261 EP - 269 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-16192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Dreßler, Martin A1 - Sojref, Regine A1 - Feigl, Michael A1 - Saliwan Neumann, Romeo A1 - Hünert, Daniela A1 - Schulz, Wencke T1 - High-temperature performance of alumina coatings on Ni-base superalloys T2 - Tagung "Materials Science and Engineering" CY - Nuremberg, Germany DA - 2008-09-01 PY - 2008 AN - OPUS4-17653 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian T1 - Influence of polyvinylpyrrolidone (PVP) on alumina sols prepared by a modified Yoldas procedure N2 - Al13 polycations containing alumina sols, prepared by a modified Yoldas procedure were mixed with polyvinylpyrrolidone (PVP). Although Al speciation in freshly prepared sols was not affected by PVP addition the decay rate of Al13 polycations was slightly decreased in PVP-containing sols. PVP does not show any influence on particle size and particle growth. The influence of PVP addition on viscosity and flow behavior of modified Yoldas sols depends on their solids content and NO3-/Al molar ratio. KW - ModifiedYoldas sols KW - PVP KW - NMR KW - Rheology KW - Particle size KW - Aging PY - 2008 U6 - https://doi.org/10.1007/s10971-008-1798-9 SN - 0928-0707 SN - 1573-4846 VL - 47 IS - 3 SP - 260 EP - 267 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-17854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Influence of sol-gel derived alumina coatings on oxide scale growth of nickel-base superalloy Inconel-718 N2 - Alumina coatings with differing phase compositions were deposited on Inconel-718 (IN-718) Ni-base superalloy substrates using sol–gel processing. Mass gain measurements served for studying the oxidation behavior of coated metal surfaces if exposed to 800°C and 900°C for up to 4000 h in static air. Itwas found, that alumina coatings significantly reduce the oxidation related mass gain of IN-718 even after heating to 900°C for 4000 h. Transmission electron microscopy (TEM) studies revealed diffusion of elements from the metal substrate (IN-718) into the alumina coatings and — to a much lower degree — from the coating into the substrate. These diffusion processes are greatly influenced by the phase composition of the coatings, especially by the presence of alpha-alumina. KW - Oxide scale growth KW - Inconel-718 KW - Alumina coating KW - TEM PY - 2008 U6 - https://doi.org/10.1016/surfcoat.2008.07.018 SN - 0257-8972 VL - 202 SP - 6095 EP - 6102 PB - Elsevier Science CY - Lausanne AN - OPUS4-17857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bricks, J.L. A1 - Kovalchuck, Anton V. A1 - Trieflinger, C. A1 - Nofz, Marianne A1 - Büschel, M. A1 - Tolmachev, A.I. A1 - Daub, J. A1 - Rurack, Knut T1 - On the Development of Sensor Molecules that Display FeIII-amplified Fluorescence N2 - Incorporation of a tailor-made size-restricted dithia-aza-oxa macrocycle, 1-oxa-4,10-dithia-7-aza-cyclododecane, via a phenyl linker into two fluorescent sensor molecules with electronically decoupled, rigidly fixed, and sterically preoriented architectures, a 1,3,5-triaryl-2-pyrazoline and a meso-substituted boron-dipyrromethene (BDP), yields amplified fluorescence in the red-visible spectral range upon binding of FeIII ions. The response to FeIII and potentially interfering metal ions is studied in highly polar aprotic and protic solvents for both probes as well as in neat and buffered aqueous solution for one of the sensor molecules, the BDP derivative. In organic solvents, the fluorescence of both indicators is quenched by an intramolecular charge or electron transfer in the excited state and coordination of FeIII leads to a revival of their fluorescence without pronounced spectral shifts. Most remarkably, the unbound BDP derivative shows dual emission in water and can be employed for the selective ratiometric signaling of FeIII in buffered aqueous solutions. KW - Fluoreszenz KW - Eisen KW - Fluoreszenzmarker PY - 2005 U6 - https://doi.org/10.1021/ja050652t SN - 0002-7863 SN - 1520-5126 VL - 127 SP - 13522 EP - 13529 PB - American Chemical Society CY - Washington, DC AN - OPUS4-12180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Nofz, Marianne T1 - Laboratory Intercomparison on the Determination of the Fe(II)/Fe(III) Ratio in Glass Using Mössbauer Spectroscopy N2 - The Mössbauer community all over the world was given the opportunity to determine the Fe(II)/Fe(III) ratio in 4 glass samples of different total iron content, to classify themselves with respect to their measurement technique and especially to their kind of evaluation. KW - Mössbauer spectroscopy KW - Iron KW - Glass KW - Intercomparison KW - Fe(II)/Fe(III) ratio PY - 2004 U6 - https://doi.org/10.1023/B:HYPE.0000043252.55048.63 SN - 0304-3843 SN - 1572-9540 VL - 156-157 SP - 347 EP - 352 PB - Kluwer CY - Dordrecht AN - OPUS4-4579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Dreßler, Martin A1 - Jäger, Christian A1 - Altenburg, Wolfgang T1 - 27Al NMR Study of Al-Speciation in Aqueous Alumina-Sols N2 - A new method of preparing concentrated alumo-sols, the hydrolysis of Al-tri-sec-butylate in acidic aqueous media at 85°C, was studied in detail by varying the H2O/Al- and NO3 -/Al-ratios in wide ranges. The components of the sols were characterized by 27Al NMR spectroscopy. The pH-value depends on both the chosen H2O/Al- and NO3 -/Al-ratio and on the aging time of the sols and reflects the composition of the sols. Al13 polycations were detected in sols with a pH-value between 3.0 and 3.7. As a new result its presence was shown by NMR below 3.4. The Al13 content of the sols increased with pH and the maximum fraction of Al13 polycations was detected in the sol with the highest pH (3.7). Nearly 65% of the entire aluminium content of this solution is bound in the Al13 polycations. Hence, a new synthetic method for the preparation of Al13 ions containing sols was developed. Aging studies of the sols showed, that the Al13 polycations were more stable in solutions with higher pH-value. Al13 polycations were detected after an aging time of four months only in sols with a pH-value of 3.7. Tempering the aged sols at 40° to 80°C caused formation of Al13 and also of Al30 polycations. KW - Alumo-sol KW - Al13 polycations KW - Al-27 NMR spectroscopy PY - 2006 SN - 0928-0707 SN - 1573-4846 VL - 38 IS - 1 SP - 25 EP - 35 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-12350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mosel, Günter A1 - Hübert, Thomas A1 - Nofz, Marianne A1 - Brenneis, Rudolf A1 - Köcher, Peter A1 - Kley, Gerd T1 - Zn-K EXAFS investigations on ZnS/ZnO containing vitrified ashes from municipal incinerator facilities N2 - Zn-K transmission EXAFS measurements were performed on vitrified ashes from municipal waste incinerator facilities, which contain low amounts of Zn (up to 3 wt%) and sulphur (up to 0.5 wt%) in a ZnS phase. From the Fourier transform it can be concluded that the zinc ions are fourfold co-ordinated by oxygen or sulphur ions. The amount of zinc ions of sulphur environment, e.g. the concentration of ZnS, was determined by Fourier filtering and subsequent parameter fitting. A quantitative analysis of low ZnS concentrations up to 1 wt% has been performed for samples with a molar ratio Zn/S < 5. PY - 2001 U6 - https://doi.org/10.1023/A:1011802202743 SN - 0022-2461 SN - 1573-4803 VL - 36 SP - 5017 EP - 5025 PB - Springer Science + Business Media B.V. CY - Norwell, Mass. AN - OPUS4-18579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Stößer, R. A1 - Feist, M. A1 - Menzel, Michael A1 - Renz, F. T1 - Competing redox reactions in Fe-containing AlO(OH) and Al2O3 matrices: A combined investigation by Mössbauer, ESR spectroscopy and thermal analysis T2 - Intern. Conf. of the Application of the Mössbauer Effect (ICAME 2009) CY - Vienna, Austria DA - 2009-07-19 PY - 2009 AN - OPUS4-19694 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dreßler, Martin A1 - Hünert, Daniela A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Sol-gel alumina coatings for high-temperature corrosion protection of Ni-base alloy SC16 in water vapour containing atmosphere N2 - Alumosols in combination with well dispersed corundum were successfully used to form up to 2.5 ìm thick coatings on the Ni-base alloy SC16. These coatings withstood heat treatments at 700 °C in a water vapour containing atmosphere. The heat treatment caused formation of delta-alumina in the coating and diffusion of chromium and titanium into the coating. KW - Alumina KW - Coating KW - Sol-gel KW - Corrosion KW - Protection PY - 2009 SN - 0020-5214 VL - 58 IS - 4 SP - 192 EP - 195 PB - DVS-Verl. CY - Düsseldorf AN - OPUS4-19726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Feist, M. A1 - Menzel, Michael A1 - Nofz, Marianne T1 - Fe3+ ions acting as probes and agents in aggregation processes and solid-state reactions in AlO(OH)/Al2O3 matrices N2 - The fate of doped iron species during various mechanically and thermally initiated redox reactions and aggregation processes in crystalline and amorphous AlO(OH) or Al2O3 matrices was investigated. The amorphization of the matrix was performed by chemical (i.e., via sol-gel processes) or mechanochemical treatment (high-energy ball milling). Thermal analysis, coupled with mass spectrometry (TA-MS), Mössbauer spectroscopy, and electron spin resonance (ESR), was used. The TA under various gas atmospheres allowed preparing samples under a controlled temperature regime, together with a controlled gas influence. Both the effect of mechanical activation and the influence of the iron doping could be followed macroscopically via the down-shift of the peak temperature of the corundum formation. The ESR data characterize the Fe3+ ions and their interaction with the magnetic surrounding based on the fine structure parameters. The Mössbauer data allowed the characterization of the Fe(0), Fe2+, and Fe3+ species, together with providing information about their coordinative surrounding. Both methods provided general complementary spectroscopical information. Unexpectedly, (FeOx)n and (FexAl1-x)2O3 aggregates could also be detected in the range of low Fe concentrations. It was demonstrated that even in the low-level doped systems [(FexAl1-x)2O3 with x ≥ 0.01], all the essential spectroscopic phenomena occur. At higher Fe concentrations, they were discovered to be caused by magnetic and spin exchange interactions as well as by solid-state reactions during and after the mechanical activation. PY - 2010 U6 - https://doi.org/10.1111/j.1551-2916.2009.03596.x SN - 0002-7820 SN - 1551-2916 VL - 93 IS - 5 SP - 1447 EP - 1456 PB - Blackwell Publishing CY - Malden AN - OPUS4-21235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Diffusion of Cr, Fe, and Ti ions from Ni-base alloy inconel-718 into a transition alumina coating N2 - Heat treating metals at high temperatures trigger diffusion processes which may lead to the formation of oxide layers. In this work the diffusion of Cr, Fe and Ti into an alumina coating applied to Inconel-718 is being investigated. Mass gain measurements, UV–vis spectroscopy and transmission electron microscopy were applied in order to study the evolution of the diffusion process. It was found that mainly Cr as well as minor amounts of Fe and Ti are being incorporated into the alumina coating upon prolonged heat treatment at 700 °C. It could be shown that alumina coatings being void of Cr have the same oxidation related mass gain as uncoated samples. However, incorporation of Cr into the alumina coating decreased their mass gain below that of uncoated substrates forming a Cr oxide scale only. KW - Diffusion KW - UV–vis spectroscopy KW - Transmission electron microscopy KW - Alumina coatings KW - Sol-gel deposition PY - 2012 U6 - https://doi.org/10.1016/j.tsf.2012.02.006 SN - 0040-6090 VL - 520 IS - 13 SP - 4344 EP - 4349 PB - Elsevier CY - Amsterdam AN - OPUS4-25830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Nofz, Marianne A1 - Kranzmann, Axel T1 - Influence of a sol-gel alumina coating on oxidation of X20CrMoV12-1 in air up to 650 °C N2 - The need for a more efficient coal power plant generation (e.g. oxyfuel technology) results in modified process parameters and enhanced corrosion. To reach the necessary service life of high temperature parts protective coatings may be a sufficient technical solution. A modified Yoldas sol (Al2O3 based) was used to coat X20CrMoV12-1 by spin coating. After appropriate heat treatments transition alumina coatings being about 400 nm thick were obtained. Oxidation studies were carried out in laboratory air at temperatures up to 650 °C for up to 500 h exposure time. In case of the uncoated sample a rough oxide layer formed on the surface and a remarkable weight gain (2.62 mg/cm²) were detected. The sol–gel alumina layer (mainly δ-Al2O3) demonstrated a high protection, i.e. a very low weight gain (0.05 mg/cm²). Diffusion of alloying elements into the coating was observed. No indication of spallation of the coating occurred. Local defects (2 µm–30 µm) in the coating led to the formation of iron-oxide islands. KW - X20CrMoV12-1 KW - Sol-gel deposition KW - Alumina KW - Air oxidation KW - Transmission electron microscopy KW - Chromium KW - Diffusion KW - Manganese PY - 2013 U6 - https://doi.org/10.1016/j.tsf.2013.04.132 SN - 0040-6090 VL - 539 SP - 29 EP - 34 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-29162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Kohl, Anka T1 - Short-term exposure tests of ɣ-Al2O3 Sol-gel coating on X20Cr13 in artificial geothermal waters with different pH N2 - The suitability of an Al2O3 coating for corrosion protection on X20Cr13 was evaluated in various artificial geothermal brines, focusing on the influence of different pH (4, 6 and 8) and their chemical compositions on the coating properties. All experiments were performed in the laboratory using autoclaves at 150 ◦C and 1 MPa in deaerated condition for 1 and 7 days. Results showed that the pH of geothermal waters is the most detrimental factor in the transformation of ɣ-Al2O3 and its protective abilities. Delaminations were found in the Coating exposed to geothermal brines with pH 4. FTIR spectra indicated a transformation of ɣ-Al2O3 to boehmite AlOOH after exposure to pH 4 and 6, and bayerite Al(OH)3 was formed after exposure to pH 8. Different Crystal structures of the hydrated Al2O3 also contribute to the stability of the coatings, observed by the SEM- EDX of the surface and cross-section of coatings. This study indicated that ɣ-Al2O3 sol-gel coating presents a promising aspect of corrosion protection in geothermal environment with a neutral pH. KW - Al2O3 KW - Corrosion KW - Coating KW - Martensitic steel PY - 2021 U6 - https://doi.org/10.1016/j.geothermics.2021.102193 SN - 0375-6505 VL - 96 SP - 102193 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-52931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heuser, Lina A1 - Nofz, Marianne A1 - Müller, Ralf A1 - Deubener, J. T1 - Silver dissolution and precipitation in an Na2O–ZnO–B2O3 metallization paste glass N2 - Thermally stimulated interactions between silver and glass, that is, silver dissolution as Ag+ and precipitation as Ag0 were studied in two glass series of molar target composition xAg2O–(19 − x)Na2O–28ZnO–53B2O3 with x = 0, 0.1, 0.5, 5 and (19Na2O–28ZnO–53B2O3)+yAg2O with y = 0.01, 0.05. These act as model for low-melting borate glasses being part of metallization pastes. The occurrence of metallic silver precipitates in melt-quenched glass ingots demonstrated that silver dissolved only in traces (< 0.01 mol%) in the glasses. The dissolved silver was detected by means of Raman spectroscopy and energy-dispersive X-ray spectroscopy. Increasing x in the batch could not lead to a significant increase of the silver ion fraction in the glass as possible in binary silver borate glasses. In situ observation of heated AgNO3 mixed with the base glass frit in a hot stage microscope showed that Ag0 precipitation occurs already at the solid state. At higher temperatures, small droplets of liquid silver were found to move freely within the melt, whereas coalescence caused a stepwise increase of their size. These results contribute to the understanding of formation of silver precipitates in metallization pastes described in the literature. KW - Silver metallization paste KW - Batch reactions KW - Borate KW - Glass forming melts KW - Glass manufacturing KW - Raman spectroscopy PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-559433 SN - 2041-1286 SP - 1 EP - 11 PB - Wiley Online Library AN - OPUS4-55943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heuser, Lina A1 - Nofz, Marianne A1 - Müller, Ralf T1 - Alkali and alkaline earth zinc and lead borate glasses: Sintering and crystallization N2 - Glasses in the systems Me2O-ZnO-B2O3 with Me = Li, Na, K, Rb (MeZB), Na2O-ZnO-CuO-B2O3 (NZCuB), CaO-ZnO-B2O3 (CaZB), and Li2O-PbO-B2O3 (LPbB) as a reference, were studied by differential thermal analysis, dilatometry, rotational viscometry, and heating microscopy. A decrease of viscosity and sintering range was found with decreasing number of fourfold coordinated boron. The viscosity of the alkali zinc borate glasses varies only slightly. LPbB and CaZB stand out by their reduced and increased viscosities, respectively. Sodium, potassium, and calcium zinc borate glasses possess a fragility above 76. All glasses were sintered to full density before crystallization. Mostly binary zinc borate phases govern crystallization. A ternary crystalline phase was detected only in the potassium containing sample. The Weinberg glass stability parameter ranges between 0.07 and 0.12. This is caused by the presence of several crystalline phases and varying melting points of even the same crystalline phase in different glass matrices. KW - Alkali zinc borate glasses KW - Lead borate glasses KW - Viscosity KW - Sintering KW - Crystallization KW - Fragility PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556128 SN - 2590-1591 VL - 15 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-55612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heuser, Lina A1 - Nofz, Marianne T1 - Alkali and alkaline earth zinc and lead borate glasses: Structure and properties N2 - Low melting Li2O-PbO-B2O3, Me2O-ZnO-B2O3, Me = Li, Na, K, Rb and CaO-ZnO-B2O3 glasses were studied with Raman and infrared spectroscopies to advance the structural understanding of zinc borate glasses as potential candidates for substitution of lead containing glasses. Although the effect of type of alkali ions on the number (N4) of fourfold coordinated boron (B4) in the glasses is small, the alkali ions direct the type of borate groups, i.e., pentaborate in lithium, sodium, and calcium zinc borate glasses, as well as diborate in potassium and rubidium containing ones. Both groups were simultaneously found in Li2O-PbO-B2O3. Alkali ions are mainly responsible for the formation of B4-units and metaborate. Zinc ions favorably compensate non-bridging oxygen and partially form ZnO4. With decreasing N4 and field strength of the alkali ions the atomic packing density, glass transition temper ature and Young’s Modulus also decrease. The coefficient of thermal expansion increases with decreasing N4. KW - Raman spectroscopy KW - IR spectroscopy KW - Alkali zinc borate glasses KW - Lead borate glasses KW - Physical properties KW - Young’s Modulus PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556109 SN - 2590-1591 VL - 15 SP - 1 EP - 12 PB - Elsevier CY - Amsterdam AN - OPUS4-55610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Nofz, Marianne ED - Klein, Lisa ED - Aparicio, Mario ED - Jitianu, Andrei T1 - Alumina thin films N2 - This chapter gives an overview over preparation, properties and applications of alumina thin films. The preparation of polymeric and colloidal alumina sols and their deposition on diverse substrate materials with different geometries are described first. Consideration of properties (surface tension, particle size, viscosity, aging of the sols and their optimization by using certain additives) is included, too. A description of post-treatments of the coatings, which initiate phase transformations and also determine their microstructure, completes the part on coating preparation. Data on adhesion, thickness, surface roughness and mechanical, textural as well as optical properties of alumina thin films are provided in a further paragraph. In a third main part experience concerning possible applications, such as (i) membranes for catalysis, separation and filtration, (ii) barrier layers against electrochemical and high temperature corrosion or inter-diffusion of ions between different phases, (iii) mechanical protection, (iv) sensor construction, (v) improvement of optical properties, as well as (vi) achieving water repellency is summarized. KW - Sol-gel coating KW - Alumina KW - Thin film PY - 2016 SN - 978-3-319-19454-7 U6 - https://doi.org/10.1007/978-3-319-19454-7_133-1 SP - 1 EP - 44 PB - Springer International Publishing CY - Schweiz ET - 2. Auflage AN - OPUS4-37552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Davydenko, L. A1 - Nazarchuk, M. A1 - Nasiedkin, D. A1 - Plyuto, Y. A1 - Mosquera Feijoo, Maria A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel A1 - Pérez, F.J. T1 - Anticorrosion hybrid AlPO4/Al2O3 coatings on the surface of P92 steel for oxy-fuel power plant application T2 - XtremeCOAT 2014 - Surface engineering for functional applications under extreme conditions CY - Madrid, Spain DA - 2014-10-20 KW - Corrosion protection KW - Hybrid coatings KW - Boehmite KW - AlPO4 PY - 2014 SP - P 5, 1 EP - 2 AN - OPUS4-31453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Menzel, Michael A1 - Feist, M. A1 - Nofz, Marianne A1 - Renz, F. T1 - Competing redox reactions in Fe-containing AlO(OH) and Al2O3 matrices: A combined investigation by Mössbauer, ESR spectroscopy and thermal analysis N2 - The investigation of iron-doped AlO(OH)/Al2O3 systems revealed that the combined employment of Mössbauer and ESR spectroscopies together with thermal analysis yields meaningful data with complementary information. This mutual complementarity is based on the coexistence of Fe point defects with the corresponding aggregated FeOx species which has been observed even for very low Fe concentrations. Competing redox processes between the dopant, the AlOx matrix, and the gas atmosphere during the thermal treatment enable the generation of solid phases exhibiting specific chemical properties. The entire reaction process is influenced by a specific mechanical and thermal pre-treatment that affects predominantly oxydative processes in the matrix. A protecting influence of the matrix preventing further reductive attack of the Fe3+ Fe2+ ions by hydrogen has been established. KW - Mössbauer KW - ESR spectroscopy KW - Thermal analysis KW - Al2O3 KW - Magnetite KW - Fe(0) KW - Fe(2+) KW - Fe(3+) PY - 2010 UR - http://iopscience.iop.org/1742-6596/217/1/012028/pdf/1742-6596_217_1_012028.pdf U6 - https://doi.org/10.1088/1742-6596/217/1/012028 SN - 1742-6588 SN - 1742-6596 VL - 217 IS - 1 SP - 012028-1 - 012028-5 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-21876 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 - Feigl, Michael A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Kohl, Anka T1 - Improved wetting of bare and pre-coated steels by aqueous alumina sols for optimum coating success N2 - Alumina coatings are a promising candidate for the protection of metals prone to high temperature corrosion. If applied via sol–gel process, especially by using so called aqueous modified Yoldas-sols, the deposition is hardened by differences in surface free energy of substrate and sol. In this paper the apparent surface properties of samples to be coated and sols were examined by contact angle measurements, IR-spectroscopy and tensiometry. The results imply, after consideration of possible uncertainties, the use of surface tension reducing 2-butanol already present during hydrolysis of the sols to obtain an easy and successful coating process. KW - Sol-gel KW - Wetting KW - Coating KW - IR-spectroscopy PY - 2010 U6 - https://doi.org/10.1007/s10971-010-2232-7 SN - 0928-0707 SN - 1573-4846 VL - 55 IS - 2 SP - 191 EP - 198 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-22602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Jäger, Christian A1 - Deubener, J. T1 - Eigenschaftsanomalien für CaO-Al2O3-B203-SiO2-Gläser mit variiertem Al2O3-Gehalt T2 - 85. Glastechnische Tagung CY - Saarbrücken, Germany DA - 2011-05-30 PY - 2011 AN - OPUS4-24011 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Nofz, Marianne A1 - Kranzmann, Axel T1 - Alumina coatings against carburization and oxidation under oxyfuel conditions T2 - 1st International conference on materials for energy CY - Karlsruhe, Germany DA - 2010-07-04 PY - 2010 SN - 978-3-89746-117-8 SP - 1012 AN - OPUS4-24179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Feigl, Michael A1 - Pulz, Robert A1 - Rehmer, Birgit A1 - Sojref, Regine A1 - Dörfel, Ilona T1 - Verhalten von Al2O3-Sol-Gel-Schichten auf Nickelbasislegierungen bei thermomechanischer Belastung T2 - Workshop "Materialien und Prozesstechniken der Turbinenschaufel-beschichtung" der Europ. Forschungsges. Dünne Schichten e. V. CY - Dresden, Germany DA - 2011-03-15 PY - 2011 AN - OPUS4-23493 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Feigl, Michael A1 - Dreßler, Martin A1 - Dörfel, Ilona T1 - Sol-Gel-Aluminiumoxidschichten für den Oxidationsschutz von Hochtemperaturlegierungen, Teil 2 KW - Alumosol KW - Sol-Gel-Verfahren KW - Beschichtung KW - Oxidationsschutz PY - 2009 SN - 0023-0561 VL - 61 IS - 5 SP - 272 EP - 277 PB - DVS-Verl. CY - Düsseldorf AN - OPUS4-20263 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Feigl, Michael A1 - Dreßler, Martin A1 - Dörfel, Ilona T1 - Sol-Gel-Aluminiumoxidschichten für den Oxidationsschutz von Hochtemperaturlegierungen, Teil 1 KW - Alumosol KW - Sol-Gel-Verfahren KW - Beschichtung KW - Oxidationsschutz PY - 2009 SN - 0023-0561 VL - 61 IS - 2-3 SP - 82 EP - 86 PB - DVS-Verl. CY - Düsseldorf AN - OPUS4-20264 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Aluminiumoxid als Schutzschicht für kommerzielle Kraftwerksstähle (Teil 1) N2 - In Kohlekraftwerken mit Oxyfuel-Technologie erfolgt die Verbrennung unter Zufuhr von reinem Sauerstoff. Damit steht für die Abscheidung und Speicherung von CO2 ein Rauchgas mit hohem CO2-Anteil zur Verfügung (CCS-Technologie). Aufgrund dieses Verbrennungsprozesses ändert sich im Wesentlichen die Rauchgaszusammensetzung hin zu hohem H2O- und SO2 -Anteil. Deshalb wurden in verschiedenen Laboratorien kommerzielle Kraftwerksstähle unter den entsprechenden korrosiven Bedingungen getestet. Im Vergleich zur herkömmlichen Verbrennungsmethode zeigten die ferritisch-martensitischen Stähle schon nach 1000 h Auslagerungszeit unter Oxyfuel-Bedingungen eine durch einen deutlich erhöhten Materialverlust gekennzeichnete Korrosion. Eine Möglichkeit um dennoch die Lebensdauer dieser Stähle zu gewährleisten, besteht im Aufbringen geeigneter Schutzschichten auf die Stahloberfläche. Die vorliegende Arbeit befasst sich mit der Herstellung und Bewertung von Sol-Gel-Aluminiumoxidschichten als Schutz vor Korrosion in Oxyfuel-Rauchgas-Atmosphäre. Diese wurden auf den warmfesten Stahl X20CrMoV12-1 (X20) mittels der Tauchmethode aufgebracht. Anschließend erfolgte eine Auslagerung der beschichteten Proben für 1000 h bei 600 °C in einer H2O-CO2-O2-SO2 -Atmosphäre. Im Vergleich zum unbeschichteten Stahl X20 war der Materialverlust des beschichteten Stahls deutlich geringer. Insbesondere konnte durch die Aluminiumoxidschicht der Transport von CO2 und SO2 zur Stahloberfläche verhindert werden. KW - Stahl KW - Korrosion KW - Aluminiumoxid KW - Sol-Gel PY - 2016 SN - 0016-4232 VL - 107 IS - 9 SP - 1900 EP - 1903 PB - Leuze Verlag CY - Bad Saulgau AN - OPUS4-38148 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel ED - Leuze-Reichert, Sylvia T1 - Aluminiumoxid als Schutzschicht für kommerzielle Kraftwerksstähle (Teil 2) N2 - In Kohlekraftwerken mit Oxyfuel-Technologie erfolgt die Verbrennung unter Zufuhr von reinem Sauerstoff. Damit steht für die Abscheidung und Speicherung von CO2 ein Rauchgas mit hohem CO2-Anteil zur Verfügung (CCS-Technologie). Aufgrund dieses Verbrennungsprozesses ändert sich im Wesentlichen die Rauchgaszusammensetzung hin zu hohem H2O- und SO2 -Anteil. Deshalb wurden in verschiedenen Laboratorien kommerzielle Kraftwerksstähle unter den entsprechenden korrosiven Bedingungen getestet. Im Vergleich zur herkömmlichen Verbrennungsmethode zeigten die ferritisch-martensitischen Stähle schon nach 1000 h Auslagerungszeit unter Oxyfuel-Bedingungen eine durch einen deutlich erhöhten Materialverlust gekennzeichnete Korrosion. Eine Möglichkeit um dennoch die Lebensdauer dieser Stähle zu gewährleisten, besteht im Aufbringen geeigneter Schutzschichten auf die Stahloberfläche. Die vorliegende Arbeit befasst sich mit der Herstellung und Bewertung von Sol-Gel-Aluminiumoxidschichten als Schutz vor Korrosion in Oxyfuel-Rauchgas-Atmosphäre. Diese wurden auf den warmfesten Stahl X20CrMoV12-1 (X20) mittels der Tauchmethode aufgebracht. Anschließend erfolgte eine Auslagerung der beschichteten Proben für 1000 h bei 600 °C in einer H2O-CO2-O2-SO2 -Atmosphäre. Im Vergleich zum unbeschichteten Stahl X20 war der Materialverlust des beschichteten Stahls deutlich geringer. Insbesondere konnte durch die Aluminiumoxidschicht der Transport von CO2 und SO2 zur Stahloberfläche verhindert werden. KW - Stahl KW - Korrosion KW - Aluminiumoxid KW - Sol-Gel PY - 2016 SN - 0016-4232 VL - 107 IS - 10 SP - 2098 EP - 2102 PB - Leuze-Verlag CY - Bad Saulgau AN - OPUS4-38149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Mosquera Feijoo, Maria A1 - Sojref, Regine A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Alumina sol-gel coatings for corrosion protection of steel P92 T2 - MSE Congress 2014 CY - Darmstadt, Germany DA - 2014-09-23 PY - 2014 AN - OPUS4-32387 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Geipel, Ch. T1 - Evaluation of protective sol-gel alumina coatings on Inconel 625 using electron microscopy and gloss measurement T2 - MSE Congress 2014 CY - Darmstadt, Germany DA - 2014-09-23 PY - 2014 AN - OPUS4-32388 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sojref, Regine A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Schulz, Wencke A1 - Wollschläger, Nicole A1 - Kranzmann, Axel T1 - Thin and porous sol-gel alumina coatings on a 9% Cr steel as a protection against high-temperature corrosion in power plants N2 - In order to reduce CO2 emissions fossil fuelled power stations with high combustion efficiency are being developed. The increase of the operating temperature, a common way to improve combustion efficiency, leads to enhanced corrosion of heat exchange steel tubes in the power plants. Within the framework of the European project “Production of Coatings for New Efficient and Clean Coal Power Plant Materials” (POEMA)", high temperature corrosion protection coatings are now under investigation. Thin porous sol-gel alumina films are promising candidate coating materials. Coatings were prepared by applying boehmite sols on grinded steel P92 and subsequent heat treatments at temperatures up to 650 °C. Thus a porous layer of worm-like particles was formed consisting of nano-crystallites and amorphous alumina. A dense interface with satisfying adhesion resulted from diffusion of chromium and iron ions out of the steel into the porous coating. However, the film locally exhibited some cracks caused by steep edges in the grinded steel surface. An appropriate substrate pretreatment should avoid this problem. The protection of the steel relies on the barrier function of the alumina coating and the formation of a dense chromia layer at the steel surface. T2 - ICC6 6th International Congress on Ceramics CY - Dresden, Germany DA - 21.08.2016 KW - High-temperature corrosion KW - Alumina KW - Chromium PY - 2016 AN - OPUS4-38354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pönitzsch, A. A1 - Nofz, Marianne A1 - Wondraczek, L. A1 - Deubener, J. T1 - Bulk elastic properties, hardness and fatigue of calcium aluminosilicate glasses in the intermediate-silica range N2 - Bulk elastic properties, hardness and fatigue of calcium aluminosilicate (CAS) glasses in the technically relevant region of the ternary with intermediate-silica fraction were determined by combining results of Vickers indentation, ultrasonic echography and Archimedian buoyancy at room temperature. Of three studied compositional series, the first series was along the meta-aluminous join, while in the two other series the molar fraction of SiO2 was kept constant. For the first series the elastic moduli and hardness show an almost linear increase with increasing SiO2 fraction. In contrast, increasing the CaO/SiO2 ratio at constant silica content results in a characteristic change when passing the meta-aluminous join. Elastic constants and hardness were lower at the percalcic than on the peraluminous side. Empirical models which relate bulk elastic moduli to internal energy, short-range inter-atomic forces and the packing density of their oxide constituents were found to be in agreement with the experimental data for meta-aluminous glasses, while deviations between the observed and predicted trends were evident for percalcic compositions. Empirical fatigue parameters such as the probability to initiate cracks after indentation reflect the bulk mechanical properties in the CAS system when conducted in inert atmosphere, but are otherwise clearly dominated by environmental effects KW - Aluminosilicate glasses KW - Elastic constants KW - Indentation KW - Hardness KW - Crack initiation KW - Sub-critical crack-growth PY - 2016 U6 - https://doi.org/10.1016/j.jnoncrysol.2015.12.002 SN - 0022-3093 VL - 434 SP - 1 EP - 12 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-35243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Zietelmann, Christina A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Microstructural origin of time-dependent changes in alumina sol-gel-coated Inconel 718 exposed to NaCl solution N2 - Inconel 718 was spin coated twice and fourfold with a sol to obtain 200- and 400-nm-thick transition alumina films on the surface. Bare and sol–gel alumina-coated Inconel 718 samples were exposed to NaCl solution to study their corrosion behavior by means of electrochemical impedance spectroscopy. In combination with scanning electron microscopy, it was shown that bare Inconel 718 is after initial passivation prone to pitting corrosion. For the coated Inconel 718 samples, an improvement in the protective effect of the coatings with time was observed. This observation is in contradiction to the results of other authors who observed degradation of alumina coatings exposed to NaCl solution with time. Transmission electron microscopy revealed a formation of (1) a compacted region at the coating surface as well as (2) a chromium-rich region at the interface between coating and alloy during the contact with a NaCl solution. The last one mainly contributes to the observed chronological sequence of electrochemical characteristics of the samples. KW - Alumina coatings KW - Superalloys KW - Corrosion protection KW - EIS KW - SEM KW - TEM PY - 2015 U6 - https://doi.org/10.1007/s10971-015-3668-6 SN - 0928-0707 SN - 1573-4846 VL - 75 IS - 1 SP - 6 EP - 16 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-33338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Wollschläger, Nicole A1 - Mosquera Feijoo, Maria A1 - Kranzmann, Axel T1 - Microstructure, smoothening effect, and local defects of alumina sol-gel coatings on ground steel N2 - Porous alumina films with thicknesses of a few microns were prepared via a dip-coating technique on steel P92. The coating is shown to protect the steel against massive corrosion, which is typical in the hot reactive environment of coal fired power plants. To mimic real conditions ground steel plates were coated with a boehmite-sol. This leads to an overall smoothing of the formerly rough surface. In the following short annealing step the inner porous construction with worm-like particles consisting of nano-crystallites and amorphous alumina is formed. Due to the simultaneous diffusion of chromium and iron ions out of the bulk steel material into the porous alumina coating, a dense interface with satisfactory adhesion is formed. However, the film exhibits few local defects like cracks or dense alumina nodules caused by steep edges in the ground surface or agglomeration of boehmite-sol components, respectively. Cracks especially have to be avoided. This problem can be overcome so far by slight modifications in the sol preparation process and surface treatment of the substrates. Nevertheless the results demonstrate the potential of sol-gel based alumina coatings as a time- and cost-saving protection type for commercial steel P92. KW - Alumina coating KW - Steel protection KW - TEM PY - 2017 U6 - https://doi.org/10.1007/s10971-016-4188-8 SN - 0928-0707 VL - 81 IS - 1 SP - 185 EP - 194 PB - Springer CY - New York AN - OPUS4-40044 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 - GEN A1 - Nofz, Marianne T1 - High temperature coatings (Book review) N2 - All in all, practicing professionals as well as researchers can read this book with pleasure and great benefit. It presents a comprehensive collection of data and practical examples manifested in about 100 graphs, 80 schemes of processes and devices, a manifold of images showing the microstructure of alloys or details of components and several phase diagrams. Tables containing data on commercially available coatings, alloys, compositions of corrosive salts, function of constituents of coatings add further important pieces of information. Thus, this book is a valuable source of information for anyone engaged in work with or research on high temperature coatings. KW - Coating KW - High temperature PY - 2018 U6 - https://doi.org/10.1002/maco.201870104 SN - 0947-5117 VL - 69 IS - 10 SP - 1490 EP - 1490 PB - Wiley‐VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-46749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Bäßler, Ralph T1 - Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C N2 - Al2O3 has been widely used as a coating in industrial applications due to its excellent chemical and thermal resistance. Considering high temperatures and aggressive mediums exist in geothermal systems, Al2O3 can be a potential coating candidate to protect steels in geothermal applications. In this study, γ-Al2O3 was used as a coating on martensitic steels by applying AlOOH sol followed by a heat treatment at 600 °C. To evaluate the coating application process, one-, two-, and three-layer coatings were tested in the artificial North German Basin (NGB), containing 166 g/L Cl−, at 150 °C and 1 MPa for 168 h. To reveal the stability of the Al2O3 coating in NGB solution, three-layer coatings were used in exposure tests for 24, 168, 672, and 1296 h, followed by surface and cross-section characterization. SEM images show that the Al2O3 coating was stable up to 1296 h of exposure, where the outer layer mostly transformed into boehmite AlOOH with needle-like crystals dominating the surface. Closer analysis of cross-sections showed that the interface between each layer was affected in long-term exposure tests, which caused local delamination after 168 h of exposure. In separate experiments, electrochemical impedance spectroscopy (EIS) was performed at 150 °C to evaluate the changes of coatings within the first 24 h. Results showed that the most significant decrease in the impedance is within 6 h, which can be associated with the electrolyte penetration through the coating, followed by the formation of AlOOH. Here, results of both short-term EIS measurements (up to 24 h) and long-term exposure tests (up to 1296 h) are discussed. KW - Al2O3 KW - Geothermal KW - Martensitic steels KW - Behmite KW - Corrosion PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-525551 SN - 2079-6412 VL - 11 IS - 5 SP - 526 PB - MDPI CY - Basel AN - OPUS4-52555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Wollschläger, Nicole A1 - Mosquera Feijoo, Maria A1 - Schulz, Wencke A1 - Kranzmann, Axel T1 - Thin Sol-Gel Alumina Coating as Protection of a 9% Cr Steel Against Flue Gas Corrosion at 650 °C N2 - Samples of sol-gel alumina coated and uncoated P92 steel were exposed to flue gas at 650 °C for 300 h. As result of this treatment a 50 µm thick bi-layered oxide scale had formed on the surface of the uncoated sample. Below the scale a 40 µm thick inner oxidation zone was detected. In contrast, the porous, micron thick alumina coating enabled the formation of a chromium oxide scale with a thickness of some nanometers at the interface between steel substrate and coating. In this case high temperature corrosion of the steel was prevented so far. KW - Steel KW - Oxide coatings KW - High-temperature corrosion KW - TEM KW - SEM PY - 2018 U6 - https://doi.org/10.1007/s11085-017-9799-0 SN - 0030-770X SN - 1573-4889 VL - 89 IS - 3-4 SP - 453 EP - 470 PB - Springer AN - OPUS4-44472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wollschläger, Nicole A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Schulz, Wencke A1 - Sojref, Regine A1 - Kranzmann, Axel T1 - Exposition of sol-gel alumina-coated P92 steel to flue gas: Time-resolved microstructure evolution, defect tolerance, and repairing of the coating N2 - Technically relevant P92 steel (9% Cr) was coated with a micron-thick porous alumina layer prepared by sol-gel technique and treated with flue gas (60 CO2-30 H2O-2 O2-1 SO2-7 N2 (mole fraction in %)) at 650 ° to mimic an oxyfuelcombustion process. Local defects in the coating were marked using focused ion beam (FIB) technique and were inspected after exposition to hot flue gas atmosphere at 300, 800, and 1300 h, respectively. Local defects like agglomerated alumina sol particles tend to spall off from the coating uncovering the underlying dense chromia scale. Re-coating was found to restore the protection ability from oxidation when repeatedly treated with hot flue gas. Cracks and voids did not promote the local oxidation due to the formation of crystalline Mn/S/O species within and on top of the coating. The protective character of the steel-coating system is a result of (i) the fast formation of a dense chromia scale at the surface of sol-gel alumina-coated P92 steel bars in combination with (ii) the porous alumina coating acting as diffusion barrier, but also as diffusion partner in addition with (iii) fast Mn outward diffusion capturing the S species from flue gas. KW - Alumina coatings KW - Oxyfuel KW - Steel P92 KW - High temperature corrosion PY - 2018 U6 - https://doi.org/10.1002/maco.201709712 SN - 1521-4176 SN - 0947-5117 SN - 0043-2822 VL - 69 IS - 4 SP - 492 EP - 502 PB - Wiley-VCH Verlag GmbH&Co. KGaA CY - Weinheim AN - OPUS4-45300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Nofz, Marianne A1 - Bäßler, Ralph A1 - Sojref, Regine A1 - Le, Quynh Hoa T1 - Preliminary Study on Al2O3 Sol-Gel Coating for Corrosion Protection of Martensitic Stainless Steel in Artificial Geothermal Water N2 - Al2O3 coatings are often used as protective layers on steels against electrochemical and high-temperature corrosion because they are chemically inert and stable at elevated temperatures. This study presents preliminary work on the possibilities of using Al2O3 sol-gel coatings for corrosion protection of martensitic stainless steels in geothermal environments. Al2O3 sol-gel coatings were applied on UNS S42000, which is known to be susceptible to uniform and localized corrosion. The coated steel specimens were then tested in two types of artificial geothermal water, which simulate the geothermal fluids found in Sibayak (SBY), Indonesia, and North German Basin (NGB), Germany, respectively. SBY has pH 4 and 1.5 g/L of chloride ions, whereas NGB has a pH of 6 and 166 g/L of chloride ions. All experiments were carried out in autoclaves at 150 °C and 1 MPa under the deaerated condition. Evaluations were performed by investigating the surface profiles of both uncoated and coated steels before and after the corrosion test using a Laser Scanning Microscope (LSM) and Scanning Electron Microscope (SEM). Finally, Electrochemical Impedance Spectroscopy (EIS) was performed to compare the corrosion resistance of Al2O3 coated steels in SBY and NGB solutions. It was observed from the corrosion test that Al2O3 coatings are more suitable for use in the geothermal water with a higher pH. T2 - AMPP Annual International Corrosion Conference 2021 CY - Online Meeting DA - 19.04.2021 KW - Protective coating KW - Sol-gel coating KW - Geothermal KW - Martensitic steel KW - Corrosion PY - 2021 SP - 16777-01 EP - 16777-12 CY - Houston AN - OPUS4-52501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Saliwan Neumann, Romeo T1 - Microstructure of bare and sol-gel alumina-coated nickel-base alloy Inconel 625 after long-term oxidation at 900 °C N2 - Though Ni-base superalloys show a high oxidation and corrosion resistance, coatings could still improve these properties, especially if used at temperatures up to 1000 °C. Here, a coating was prepared by applying a boehmite-sol via dip-coating and a subsequent heat treatment at 600 °C for 30 minutes. To evaluate the coating, the oxidation behavior of bare and alumina coated Ni-base alloy Inconel 625 in air at 900 °C was studied for up to 2000 h. Electron microscopic studies of sample surfaces and cross-sections showed that (i) in the 3.5 µm – 6.3 mm thick scale formed on the bare alloy, Fe and Ni are located as fine precipitates at the grain boundaries of the chromia-rich scale, (ii) Ni and Ti are concentrated to a minor degree at the grain boundaries of the scale, too; and for the coated sample: (iii) the only 1.8 µm thick sol-gel alumina coating slows down the formation of chromia on the alloy surface and reduces the outward diffusion of the alloy constituents. The protective effect of the coating was evidenced by (i) diminished chromium diffusion at grain boundaries resulting in less pronounced string-like protrusions at the outer surface of the coated IN 625, (ii) formation of a Cr-enriched zone above the alloy surface which was thinner than the scale on the uncoated sample, (iii) no detectable Cr-depleted zone at the alloy surface, and (iv) a narrower zone of formation of Kirkendall pores. KW - Inconel 625 KW - High-temperature oxidation KW - Oxidation protection KW - Sol-gel coating PY - 2019 U6 - https://doi.org/10.1007/s11085-019-09888-z SN - 0030-770X VL - 91 IS - 3-4 SP - 395 EP - 416 PB - Springer Science+Business Media AN - OPUS4-47665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feigl, Michael A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dressler, Martin A1 - Pulz, Robert A1 - Rehmer, Birgit A1 - Feldmann, Ines A1 - Sabel, Martin T1 - Aluminiumoxidschichten für den Oxidationsschutz von Hochtemperaturlegierungen N2 - Effektive Al2O3-Keramik-Schutzschichten könnten die Verwendung preiswerterer Legierungen für Hochtemperaturanwendungen ermöglichen. Die Anforderungen an diese Schichten sind eine gute Haftung, chemische Stabilität und Dichtheit gegen die Umgebungsatmosphäre. T2 - DKG-Jahrestagung/Symposium Hochleistungskeramik CY - Aachen, Germany DA - 23.03.2009 KW - Schichtherstellung KW - Schichttestung KW - Hochtemperaturanwendungen PY - 2009 AN - OPUS4-35836 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -