TY - JOUR A1 - Blaeß, Carsten A1 - Müller, Ralf T1 - Viscous crack healing in soda–lime–magnesium–silicate–ZrO2 glass matrix composites N2 - AbstractThe present study investigates the influence of the crystal volume content on viscous crack healing in glass ceramic glass sealants. To ensure constant microstructure during healing, soda–lime–magnesium silicate glass matrix composites with varied volume fractions of ZrO2 filler particles were used. Crack healing was studied on radial cracks induced by Vickers indentation, which were stepwise annealed to monitor the healing progress by confocal laser scanning microscopy. Confirming previous studies, healing of radial cracks in pure glass was found delayed by global flow phenomena like crack widening and crack edge and tip rounding to minimize the sample surface. With increasing ZrO2 filler content, these global flow phenomena were progressively inhibited whereas local flow phenomena like sharp crack tip healing could still occur. As a result, crack healing was even accelerated by filler particles up to a maximum filler content of 17 vol% whereas crack healing was fully suppressed only at 33 vol% filler content. KW - Crack healing KW - Glass matrix composite KW - Solid oxide fuell cell KW - Vickers identation KW - Viscosity PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607860 DO - https://doi.org/10.1111/jace.20002 SN - 0002-7820 SP - 1 EP - 12 PB - Wiley AN - OPUS4-60786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gogula, Shravya A1 - Bornhöft, H. A1 - Wondraczek, L. A1 - Sierka, M. A1 - Diegeler, A. A1 - Müller, Ralf A1 - Deubener, J. T1 - Optical Real-Time Castability Evaluation for High-Throughput Glass Melting N2 - A novel optical real-time method for evaluating the castability of glass forming melts for laboratory furnaces is presented. The method is based on the analysis of top view images of the melt surface inside the crucible during melting after being subjected to a small mechanical impulse. In this way, the melt surface is excited to oscillate. The difference in contrast between two images taken in quick succession scales with the viscosity, with a larger diffe­rence occurring at lower viscosities. The method is designed as an instrument for the in-line evaluation of the castability for a high-throughput glass melting system as part of the joint project “GlasDigital” in the framework of the German Platform Material Digital initiative but is applicable to other laboratory furnaces as well. KW - Optical Real-Time Castability Check KW - Image Analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618659 DO - https://doi.org/10.52825/glass-europe.v2i.1359 VL - 2 SP - 83 EP - 93 AN - OPUS4-61865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ried, Peter A1 - Gaber, Martin A1 - Beyer, Katrin A1 - Müller, Ralf A1 - Kipphardt, Heinrich A1 - Kannengießer, Thomas T1 - Thermo Analytic Investigation of Hydrogen Effusion Behavior - Sensor Evaluation and Calibration N2 - The well established carrier gas analysis (CGA) method was used to test different hydrogen detectors comprising a thermal conductivity detector (TCD) and a metal oxide semiconducting (MOx) sensor. The MOx sensor provides high hydrogen sensitivity and selectivity, whereas the TCD exhibits a much shorter response time and a linear hydrogen concentration dependency. Therefore, the TCD was used for quantitative hydrogen concentration measurements above 50?µmol/mol. The respective calibration was made using N2/H2 gas mixtures. Furthermore, the hydrogen content and degassing behaviour of titanium hydride (TiH2-x) was studied. This material turned out to be a potential candidate for a solid sample calibration. Vacuum hot extraction (VHE) coupled with a mass spectrometer (MS) was then calibrated with TiH2-x as transfer standard. The calibration was applied for the evaluation of the hydrogen content of austenitic steel samples (1.4301) and the comparison of CGA-TCD and VHE-MS. KW - Hydrogen KW - Steel KW - Vacuum hot extraction KW - Carrier gas analysis KW - Titanium hydride KW - Gas calibration PY - 2011 DO - https://doi.org/10.1002/srin.201000237 SN - 1611-3683 SN - 0177-4832 VL - 82 IS - 1 SP - 14 EP - 19 PB - Verl. Stahleisen CY - Düsseldorf AN - OPUS4-23202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heunisch, Andreas A1 - Marzok, Ulrich A1 - Münchow, Marco A1 - Müller, Ralf A1 - Rabe, Torsten T1 - In situ characterization of the sintering behavior of LTCC laminates with embedded cavities by high temperature laser profilometry N2 - Three-dimensionally structured LTCC multilayer with channels and inner cavities are required for numerous applications like microreactors, microfluidic systems or sensors. For the performance of such devices, the dimensional accuracy of the embedded structures is crucial. In the green state, the desired structures can be precisely implemented in the LTCC tapes by laser cutting, punching or milling. Unfortunately, during lamination and sintering, shape integrity of cavities and channels is notably affected by warpage and deformation. To investigate the sintering behavior of structured LTCC laminates, a newly developed High Temperature Laser Profilometer (HTLP) can be used. The HTLP allows 3D in-situ shape detection of flat ceramic samples and tapes all along the sintering process. It is applicable for temperatures up to 1000 °C and sample sizes up to 200 mm × 200 mm × 10 mm. During a measurement, the rotating sample is scanned spirally by a linearly moving laser distance sensor through a slot in the furnace top wall. Distance and position values deliver a 3D surface image of the sample. Current lateral dimensions, which are determined by sintering shrinkage, can be measured continuously. Local deformation and warpage can be visualized time- and temperature-resolved. This new method was used, to analyze the sintering behavior of LTCC multilayer laminates containing large size cavities. These were fabricated out of punched green sheets by low pressure lamination without inserts. Samples with cavities of varying cross sections, as well as cavities with and without connection to the surface were observed. T2 - CICMT 2013 - IMAPS/ACerS 9th International conference and exhibition on ceramic interconnect and ceramic microsystems technologies CY - Orlando, FL, USA DA - 23.04.2013 KW - LTCC multilayer KW - Embedded cavities KW - High temperature laser profilometry KW - Low pressure lamination KW - Micro fluidics PY - 2013 DO - https://doi.org/10.4071/cicmt-tha44 SP - 275 EP - 282 AN - OPUS4-35077 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 - 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 DO - 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 - CONF A1 - Müller, Ralf T1 - Sintering and Foaming of Barium and Calcium Silicate Glass Powders T2 - IMAPS/ACerS 11th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystem Technologies (CICMT 2015) CY - Dresden, Germany DA - 2015-04-20 PY - 2015 AN - OPUS4-35197 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Behrens, H. A1 - Deubener, J. A1 - Müller, Ralf T1 - Impact of structure and relaxation on fatigue and micro-mechanical properties of oxide glasses: the role of volatiles and bonding state T2 - Kolloquium des DFG SPP1594 Ultrastrong Glasses CY - Jena, Germany DA - 2015-09-17 PY - 2015 AN - OPUS4-35203 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - Sintering and foaming of barium and calcium silicate glass powders T2 - Crystallization 2015 CY - Nagaoka, Japan DA - 2015-10-11 PY - 2015 AN - OPUS4-35198 LA - deu 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 - CONF A1 - Gaber, Martin A1 - Müller, Ralf A1 - Höland, W. T1 - Degassing phenomena during sintering and crystallization of glass powders N2 - Degassing may cause trouble in manufacture of sintered glass-ceramics via the Formation of bubbles (deteriorate mechanical strength or surface Quality) T2 - 6th Int. Otto Schott Colloquium CY - Jena, Germany DA - 06.09.1998 KW - Bulk diffusion KW - Sintering KW - Crystallization KW - Melting PY - 1998 AN - OPUS4-35785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marzok, Ulrich A1 - Müller, Ralf A1 - Schadrack, Reinhard A1 - Krauhausen, M. A1 - Reetz, R. T1 - Hochtemperatur-Laserprofilometrie für keramische Proben N2 - Das Hochtemperatur-Laserprofilometer der BAM4 ermöglicht eine 3D-Formerkennung an keramischen Folien oder anderen flachen Objekten während thermischer Behandlungen wie zum Beispiel bei laufenden Entbinderungs- oder Sinterprozessen. Mit dem Lasertriangulationssensor werden das Höhenprofil, die lateralen und axialen Schwindungen und andere charakteristische Maße der Probe wie die Folienbreite und -dicke, Abstände zwischen spezifischen Merkmalen oder Krümmungen bestimmt. Somit können insbesondere auch Deformationen und Verwerfungen der Objekte sowie Schwindungsinhomogenitäten an strukturierten Objekten erkannt und mit dem Herstellungsprozess verknüpft werden. T2 - DKG Jahrestagung 2012 CY - Nuremberg, Germany DA - 05.03.2012 KW - 3D-Formerkennung KW - Lasertriangulationssensor KW - Deformationen KW - Schwindungsinhomogenitäten PY - 2012 AN - OPUS4-35787 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 DO - 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 - Müller, Ralf T1 - Hydrogen permeability of glass measured by VHE-MS powder methods N2 - Glasses are can serve as exceptionally tight hydrogen barriers e.g. used for hydrogen storage in micro glass containers or cover glasses in micro electronic systems. Respective glass development, however, requires precise measurements of minimal hydrogen permeability, PH2. Recent studies showed that PH2 can be measured down to 2 10-21 mol s-1 Pa-1m-1 by means of Vacuum Hot Extraction (VHE) powder methods [1]. In this respect the isothermal gas release from glass powder particles is fitted in terms of classical diffusion models assuming spherical particles of uniform size thus obtaining the hydrogen diffusion coefficient, DH2. PH2 is then given by D H2 × S H2, where hydrogen solubility, SH2, is obtained from VHE studies of glass powders exposed to hydrogen atmosphere for different exposure time and hydrogen pressure. Measurements of minimal values of hydrogen permeability, however, require a careful evaluation and error discussion of this method. Against that background, we modeled hydrogen degassing during heating and subsequent isothermal annealing of glass powder particles of different shape and particle size distribution by means of COMSOL Multiphysics® [2] and verified related effects on DH2 obtained by the VHE powder method. T2 - SGT Centenary Conference, & ESG 2016 CY - Sheffield, UK DA - 4.9.2016 KW - Glass KW - Hydrogen KW - Permeability KW - Storage PY - 2016 AN - OPUS4-38307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blaeß, Carsten A1 - Boccaccini, A. R. A1 - Müller, Ralf T1 - Sintering and Crystallization of Fluoride-Containing Bioactive Glass F3 N2 - The fluoride-containing bioactive glass F3 with nominal composition (mol%) 44.8 SiO2 - 2.5 P2O3 - 36.5 CaO - 6.6 Na2O - 6.6 K2O - 3.0 CaF2 is a highly promising candidate for bone replacement applications. Its strong crystallization tendency, however, requires a thorough understanding of the interplay between glass powder particle size, surface crystallization, and sintering. Therefore, this study characterizes the sintering and crystallization of bulk specimens and various particle size fractions by differential thermal-analysis, laser scanning, electron microscopy, X-ray diffraction, and Infrared spectroscopy. Particle size fractions < 56 µm were found to fully densify, while crystals growing from the glass particle surface retard sintering of coarser fractions. Small amounts of a non-stoichiometrically calcium phosphosilicate (Ca14.92(PO4)2.35(SiO4)5.65) occurs as the primary crystal phase followed by combeite (Na4Ca4[Si6O18]) as a temporarily dominating phase. The surface crystallization of both pha­ses was found to be mainly responsible for sinter retardation. During later stages of crystallization, additional phases such as cuspidine (Ca4F2Si2O7) and silicorhenanite (Na2Ca4(PO4)2SiO4) occur, but finally monoclinic wollastonite (CaSiO3) forms as the dominant phase. KW - Bioactive Glass KW - Sintering KW - Crystallization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632482 DO - https://doi.org/10.52825/glass-europe.v3i.2564 SN - 2940-8830 VL - 3 SP - 105 EP - 124 AN - OPUS4-63248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Deubener, J. A1 - Müller, Ralf T1 - Internal friction and energy dissipation during fracture in silicate glasses N2 - To obtain a deeper insight into the nature of energy dissipation during fracture, the internal friction of 13 borosilicate, aluminosilicate, soda-lime, and lead-containing glasses, for which inert crack growth data are known, was measured using dynamic mechanical thermal analysis. For asymmetrically bent glass beams, the loss tangent, tan δ, was determined between 0.2 and 50 Hz at temperatures between 273 K and the glass transition temperature, Tg. It was found that the area under the tan δ vs T·Tg−1 curve correlates with the crack growth exponent, n, in the empirical v = v0·KIn relation between crack growth velocity, v, and stress intensity, KI, which indicates that n correlates with the degree of energy dissipation of sub-Tg relaxation phenomena. KW - Glass KW - Internal friction KW - Crack growth PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631582 DO - https://doi.org/10.1063/5.0255432 SN - 0021-9606 VL - 162 IS - 19 SP - 1 EP - 9 PB - AIP Publishing AN - OPUS4-63158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pan, Z. A1 - Waurischk, Tina A1 - Duval, A. A1 - Müller, Ralf A1 - Deubener, J. A1 - Krishnan, N. M. A. A1 - Wondraczek, K. A1 - Wondraczek, L. T1 - Precise Real‐Time Measurement of Liquid Viscosity Using Digital Video Data N2 - Quantitative knowledge of liquid viscosity is of fundamental importance in many areas of materials synthesis and processing. However, the determination of viscosity often relies on specialized experimental equipment, offline experimentation, or invasive procedures, in particular when required in extreme conditions such as at high temperature, high pressure, and in confined or corrosive environments. Here, this study proposes and validates a fast and simple method that mimics the intuitive perception of liquid flow within a quantitative framework. For this, this study employs digital video observation to derive quantitative values of the shear viscosity of liquids, with high precision and rapid acquisition rates. The technique involves capturing liquid dynamics after minor mechanical stimulation. Processed imaging data are indexed by similarity and referenced to a digital database generated with a finite element model, from which values of viscosity are obtained in line. The approach is tested on water at room temperature and on a high‐temperature glass melt. Covering a viscosity range of four orders of magnitude, both yield convincing agreement with tabulated reference data at low computational cost. KW - Image analyses KW - Liquids KW - Materials discovery KW - Similarity analyses KW - Viscosities PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634606 DO - https://doi.org/10.1002/aisy.202500297 SN - 2640-4567 SP - 1 EP - 12 PB - Wiley AN - OPUS4-63460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Deubener, J. A1 - Allix, M. A1 - Davis, M.J. A1 - Duran, A. A1 - Höche, T. A1 - Honma, T. A1 - Komatsu, T. A1 - Krüger, S. A1 - Mitra, I. A1 - Müller, Ralf A1 - Nakane, S. A1 - Pascual, M.J. A1 - Schmelzer, J.W. A1 - Zanotto, E.D. A1 - Zhou, S. T1 - Updated definition of glass-ceramics N2 - Glass-ceramics are noted for their unusual combination of properties and manifold commercialized products for consumer and specialized markets. Evolution of novel glass and ceramic processing routes, a plethora of new compositions, and unique exotic nano- and microstructures over the past 60 years led us to review the Definition of glass-ceramics. Well-established and emerging processing methods, such as co-firing, additive manufacturing, and laser patterning are analyzed concerning the core requirements of processing glass-ceramics and the Performance of the final products. In this communication, we propose a revised, updated definition of glass-ceramics, which reads “Glass-ceramics are inorganic, non-metallic materials prepared by controlled crystallization of glasses via different processing methods. They contain at least one type of functional crystalline phase and a residual glass. The volume fraction crystallized may vary from ppm to almost 100%”. KW - Glass-ceramics definition PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-464711 DO - https://doi.org/10.1016/j.jnoncrysol.2018.01.033 SN - 0022-3093 SN - 1873-4812 VL - 501 SP - 3 EP - 10 PB - Elsevier B.V. AN - OPUS4-46471 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506829 DO - https://doi.org/10.3389/fmats.2020.00066 VL - 7 SP - Articel 66 AN - OPUS4-50682 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513085 DO - https://doi.org/10.3389/fmats.2020.00268 VL - 7 SP - 268 AN - OPUS4-51308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -