TY - GEN A1 - Wäsche, Rolf A1 - Woydt, Mathias A1 - Rehmer, Birgit ED - Ewsuk, K. ED - Naito, M. ED - Kakeshita, T. ED - Kirihara, S. ED - Uematsu, K. ED - Abe, H. T1 - Characterization of the tribological interface in low wear Magneli type ceramics N2 - The tribological behaviour under dry sliding conditions of Magneli phase Ti4O7 and e-phase Ti2Cr2O7 with α-alumina as a sliding partner has been characterised at room temperature by oscillating sliding. The mechanical properties as well as Vickers hardness measurements do not reveal big differences between the materials, and 4-point bending strengths are around 200 MPa for both materials. Although the friction coefficients are in the medium range of 0.6 and do not differ much between the materials, the wear behaviour is very different. At room temperature, the wear coefficient of Ti2O7 is strongly dependent on relative humidity, and wear is highest under dry conditions when relative humidity is low as it is typically found for many ceramic materials. Ti2Cr2O7 shows remarkably different wear behaviour with the lowest wear in dry conditions. The measured coefficients of wear at low relative humidity of 4% are more than 2 orders of magnitude lower than those for Ti2O7. T2 - 3rd International conference on characterization and control of interfaces for high quality advanced materials CY - Kurashiki, Japan DA - 2009-09-06 PY - 2009 SN - 978-0-470-90917-1 VL - 219 SP - 111 EP - 116 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-21842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeisler, Peter A1 - Droste, Bernhard A1 - Rehmer, Birgit A1 - Rödel, R. ED - Droste, B. ED - Kowalewsky, H. T1 - A new fracture mechanics assessment method for ferritic steel components of type B packages T2 - PATRAM 98 - 12th International conference on the packaging and transportation of radioactive materials CY - Paris, France DA - 1998-05-10 PY - 1998 VL - 1 SP - 309 EP - 316 PB - Nuclear Technology Publishing CY - Paris, France AN - OPUS4-21558 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeisler, Peter A1 - Droste, Bernhard A1 - Rödel, Roland A1 - Rehmer, Birgit T1 - Current approval procedures for type-B packages in Germany: Selected topics T2 - PATRAM ´95 - 11th International Conference on the packaging and transportation of radioactive materials CY - Las Vegas, Nevada, USA DA - 1995-12-03 PY - 1995 SP - 488 EP - 495 AN - OPUS4-21638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Rehmer, Birgit A1 - Gower, M. A1 - Baker, G. A1 - Lodeiro, M. A1 - Aktas, A. A1 - Knaszovicka, L. A1 - Blahut, A. A1 - Monte, C. A1 - Adibekyan, A. A1 - Gutschwager, B. T1 - Characterisation of artificial defects in CFRP and GFRP sheets designed for energy applications using active thermography N2 - The increased use of fibre-reinforced plastic (FRP) composites for improved efficiency and reliability in energy related applications e.g. wind and marine turbine blades, nacelles, oil and gas flexible risers, also increases the demand for innovative non-destructive testing technologies. Thus, in order to achieve increased acceptance of suited and optimized non-destructive testing (NDT) methods in industry, the European Metrology Research Programme (EMRP) project ENG57 Validated Inspection Techniques for Composites in Energy Applications (VITCEA) deals with the development and validation of innovative NDT technologies. In this contribution, results concerning thermographic investigations at test specimens during tensile loading and active thermography testing after tensile loading are presented. Additionally, the determination of the optical properties (relative transmittance and directional spectral emissivity) of CFRP and GFRP test specimens is described. T2 - Conference QIRT 2016 CY - Gdansk, Poland DA - 04.07.2016 KW - Active thermography KW - CFRP KW - GFRP KW - Validation of methods PY - 2016 UR - http://qirt.gel.ulaval.ca/archives/qirt2016/papers/076.pdf DO - https://doi.org/10.21611/qirt.2016.076 SN - 2371-4085 SP - Paper 076, 527 EP - 536 CY - Quebec, Canada AN - OPUS4-37512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rajendran, R. A1 - Petley, V. A1 - Rehmer, Birgit T1 - Dynamic elastic properties of aero-engine metallic isotropic materials N2 - Study of elastic properties of aero-engine metallic materials is of paramount importance because it forms one of the foundations of engineering design of components. Nine isotropic aero-engine metallic materials were studied for their elastic properties for a temperature range varying from ambient to operating limit. Test was carried out in vacuum to prevent oxidation of specimens. Dimensional corrections of the specimen due to thermal expansion were taken into account. Dynamic elastic modulus was evaluated as the average of the moduli that was obtained through first flat and edge flexural mode frequencies. Dynamic shear modulus was established through the first torsional mode of frequency. KW - Dynamic elastic modulus KW - Dynamic shear modulus PY - 2012 UR - http://pil.sagepub.com/content/early/2012/07/17/1464420712454071.full.pdf+html DO - https://doi.org/10.1177/1464420712454071 SN - 2041-3076 SN - 1464-4207 SP - 1 EP - 7 PB - Sage Publ. CY - London AN - OPUS4-26237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grützner, Stefan A1 - Fedelich, Bernard A1 - Rehmer, Birgit A1 - Buchholz, B. ED - Clark, G. ED - Wang, C.H. T1 - Material modelling and lifetime prediction of Ni-base gas turbine blades under TMF conditions N2 - Under cyclic thermomechanical loading conditions, various damage mechanisms such as strain accumulation, creep cavitation, ageing, fatigue surface cracking etc. may take place in the material of a gas turbine blade. Depending on the loading conditions, all these effects can contribute to reduce the lifetime of the component. Subject of the present work is the development of a material model to describe the mechanical effects mentioned above, as well as the development of a lifetime model able to discriminate the different damage mechanisms. T2 - Fatigue 2014 - 11th International Fatigue Congress CY - Melbourne, Australia DA - 2014-03-02 KW - Creep KW - Fatigue KW - Ni-base superalloy KW - Oxidation damage KW - Ratcheting KW - Strain induced ageing KW - Viscoplastic PY - 2014 DO - https://doi.org/10.4028/www.scientific.net/AMR.891-892.1277 N1 - Serientitel: Advances materials research – Series title: Advances materials research VL - 891-892 IS - XXX. Thermomechanical Fatigue SP - 1277 EP - 1282 AN - OPUS4-30721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grützner, Stefan A1 - Rehmer, Birgit A1 - Fedelich, Bernard A1 - Mosquera Feijoo, Maria T1 - Deformation modeling and lifetime prediction of Ni-base gas turbine blade alloys under TMF-conditions N2 - Under cyclic thermomechanical loading conditions, various effects such as strain accumulation, creep damage, ageing, fatigue etc. may occur in the material of a gas turbine blade. Depending on the loading conditions, all these effects contribute to reduce the lifetime of the component. Subject of the present work is the development of a lifetime model able to discriminate between the different damage mechanisms, as well as the development of a material model to describe the mentioned effects and thus providing the input data for lifetime prediction. T2 - ASME Turbo Expo 2014 - GT2014 CY - Düsseldorf, Germany DA - 16.06.2014 KW - Ni-base super alloy KW - Viscoplastic KW - Ratcheting KW - Creep KW - Strain induced ageing KW - Fatigue KW - Oxidation damage PY - 2014 SN - 978-0-7918-4576-9 SP - GT2014-26332, 1-7 AN - OPUS4-30962 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 - TY - GEN A1 - Kramer, A. A1 - Nies, Daniel A1 - Pulz, Robert A1 - Rehmer, Birgit A1 - Stephan, Ina A1 - Maierhofer, Christiane ED - Mazal, Pavel T1 - Laser induced active thermography for the visualization of transport processes in building materials T2 - 5th International workshop of NDT experts - NDT in progress 2009 CY - Prague, Czech Republic DA - 2009-10-12 KW - Active thermography KW - Laser KW - Local thermal excitation KW - Thermal transport KW - Water transport KW - Wood preservatives PY - 2009 SN - 978-80-214-3968-9 SP - 153 EP - 162 AN - OPUS4-20337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Harrer, Andrea A1 - Nies, Daniel A1 - Pulz, Robert A1 - Kervalishvili, Guram N. A1 - Rehmer, Birgit A1 - Stephan, Ina A1 - Maierhofer, Christiane T1 - Untersuchung von Transport- und Schädigungsprozessen mittels lokal angeregter aktiver Thermografie N2 - Als schnelles und berührungsfreies Messverfahren kann die aktive Thermografie auch in-situ eingesetzt werden, d.h. während sich Materialeigenschaften aufgrund direkter oder indirekter Einflüsse ändern. In diesem Beitrag stellen wir die Methode der aktiven Thermografie mittels lokaler Laseranregung und deren Anwendung auf unterschiedliche Materialien wie Holz, Sandstein und Keramiken vor. Mit der im Folgenden beschriebenen Methode wurden der Einfluss von Holzschutzmitteln auf die thermischen Eigenschaften von Holz, Feuchtetransportprozesse in Naturstein sowie die thermischen Eigenschaften von Siliziumcarbid unterschiedlicher Dicke und von Hochtemperaturkeramiken nach zunehmender thermischer Belastung in-situ untersucht. Experimentelle Ergebnisse werden u. a. im Vergleich mit numerischen Simulationen vorgestellt. T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Deutschland DA - 2010-05-10 PY - 2010 SN - 978-3-940283-26-9 IS - DGZfP-BB 122 (P36) SP - 1 EP - 9 CY - Berlin AN - OPUS4-21888 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kindrachuk, Vitaliy A1 - Fedelich, Bernard A1 - Rehmer, Birgit A1 - Peter, Frauke T1 - Computational methods for lifetime prediction of metallic components under high-temperature fatigue N2 - The issue of service life prediction of hot metallic components subjected to cyclic loadings is addressed. Two classes of lifetime models are considered, namely, the incremental lifetime rules and the parametric models governed by the fracture mechanics concept. Examples of application to an austenitic cast iron are presented. In addition, computational techniques to accelerate the time integration of the incremental models throughout the fatigue loading history are discussed. They efficiently solve problems where a stabilized response of a component is not observed, for example due to the plastic strain which is no longer completely reversed and accumulates throughout the fatigue history. The performance of such an accelerated Integration technique is demonstrated for a finite element simulation of a viscoplastic solid under repeating loading–unloading cycles. KW - Fatigue KW - Incremental lifetime models KW - Finite element analysis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-481215 UR - https://www.mdpi.com/2075-4701/9/4/390 DO - https://doi.org/10.3390/met9040390 SN - 2075-4701 VL - 9 IS - 4 SP - 390, 1 EP - 24 PB - mdpi CY - Basel, Switzerland AN - OPUS4-48121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rehmer, Birgit T1 - Thermo-mechanical fatigue of heat resistant austenitic cast iron EN-GJSA-NiSiCr35-5-2 (Ni-Resist D-5S) N2 - Austenitic cast iron was primarily used as material for pumps and mountings due to their excellent corrosion resistance. Certain grades, especially those with spherical graphite morphology, offer also a good high temperature strength and a high scaling resistance, which opened new fields of application e.g. for casing part of gas turbines, exhaust manifolds and turbo chargers. For such applications, a high ductility and creep resistance is beneficial, as exhibited by the studied alloy EN-GJSA-XNiSiCr35-5-2. Its high Ni-content produces the austenitic matrix, while Cr increases strength, hardness and scaling resistance. The alloy is standardized according to DIN EN 13835 with respect to chemical composition and mechanical properties (strength, elongation at fracture, Young's modulus, hardness and impact energy) at room temperature. However, data on mechanical properties at high temperature were rarely published in the open literature. In a recently completed research project, we comprehensively characterized the alloy EN-GJSA-XNiSiCr35-5-2 in terms of its temperature dependent mechanical behavior concerning strength and to isothermal as well as non-isothermal fatigue behavior. The results were used to calibrate a material and lifetime model. TMF tests were carried out with a constant minimum temperature (Tmin = 400 °C) and varying maximum temperatures (Tmax = 700 °C, 800 °C, 900 °C) with hold times of 180 s at Tmax and two phase angles (in-phase (IP), 180° out-of-phase (OP)). The investigated alloy showed a strongly deviating TMF behavior as compared to ferritic SiMo alloys investigated in a previous project: the austenitic material exhibits a comparable strength under OP- and IP-TMF loading, while the ferritic alloys showed a distinct higher strength under IP- than under OP-TMF load. At Tmax = 700 °C and 900 °C, the lifetime of Ni-Resist in IP-tests is slightly longer than that of OP-tests, while it is vice versa at Tmax = 800 °C. The IP-tests at Tmax = 900 °C show a comparable lifetime as OP-tests at Tmax = 700 °C and 800 °C, which was unexpected for such a high testing temperature. When plotting the stress range versus N it becomes clear that the behavior at Tmax = 900 °C is different from the other investigated temperatures: at 700 °C and 800 °C the stress-curve exhibits a range of stabilized stress for both phase angles. This is also true for the OP-tests at Tmax = 900 °C. However, all IP-tests at Tmax = 900 °C show a continuous cyclic softening from the beginning on. The stiffness of the test pieces decrease continuously with increasing number of cycles and their surfaces show numerous cracks. Complementary metallographic investigations showed that beside classical fatigue damage with cracks initiated at the surface, intergranular creep damage was found in the volume of the test pieces. Pores and cracks are formed at grain boundaries perpendicular to the applied load. This is also a distinct difference to the SiMo alloys. T2 - 3rd International Workshop on Thermo-mechanical Fatigue CY - Berlin, Germany DA - 27.04.2016 KW - cast iron. fatigue KW - cyclic softening PY - 2016 AN - OPUS4-35912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Artzt, K. A1 - Rehmer, Birgit A1 - Haubrich, J. A1 - Ávila Calderón, Luis A1 - Schoenstein, F. A1 - Serrano-Munoz, Itziar A1 - Requena, G. A1 - Bruno, Giovanni T1 - Separation of the impact of residual stress and microstructure on the fatigue performance of LPBF Ti-6Al-4V at elevated temperature N2 - Manufacturing defects, high residual stress (RS), and microstructures affect the structural integrity of laser powder bed fusion (LPBF) Ti-6Al-4V. In this study, the individual effect of these factors on fatigue performance at elevated temperature (300 °C) was evaluated. Material in as-built condition and subjected to post-processing, including two heat treatments and hot isostatic pressing, was investigated. It was found that in the absence of tensile RS, the fatigue life at elevated temperature is primary controlled by the defects; and densification has a much stronger effect than the considered heat treatments on the improvement of the mechanical performance. KW - Additive manufacturing KW - Ti-6Al-4V KW - Residual stress KW - Fatigue performance KW - Computed tomography PY - 2021 DO - https://doi.org/10.1016/j.ijfatigue.2021.106239 SN - 0142-1123 VL - 148 SP - 106239 PB - Elsevier Ltd. AN - OPUS4-52369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rehmer, Birgit T1 - Kriechschädigung bei der thermomechanischen Ermüdung des warmfesten Gusseisens EN-GJSA-NISICR35-5-2 (Ni-Resist D-55) N2 - Die TMF-Lebensdauer des austenitischen Gusseisens Ni-Resist bei Tmin 400°C und Tmax 700, 800 und 900°C wurde untersucht. In-Phase TMF-Versuche bei Tmax 900 °C zeigten (im Gegensatz zu allen anderen TMF Versuchen) von Versuchsbeginn an eine kontinuierliche zyklische Entfestigung. Als Ursache konnte nach umfangreichen metallografischen Untersuchungen für diese Versuchsparameter eine ausgeprägte Kriechschädigung nachgewiesen werden, die bei anderen Ermüdungsversuchen so nicht auftrat. T2 - DVM Workshop "Bauteilverhalten bei thermomechanischer Ermüdung CY - Berlin, Germany DA - 06.04.2017 KW - Ermüdung KW - Kriechen PY - 2017 AN - OPUS4-40071 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. A1 - Fedelich, Bernard A1 - Finn, Monika A1 - Künecke, Georgia A1 - Rehmer, Birgit A1 - Nolze, Gert A1 - Leistner, C. A1 - Petrushin, N. A1 - Svetlov, I. T1 - Investigation of Elastic Properties of the Single-Crystal Nickel-Base Superalloy CMSX-4 in the Temperature Interval between Room Temperature and 1300 °C N2 - The elastic properties of the single-crystal nickel-base superalloy CMSX-4 used as a blade material in gas turbines were investigated by the sonic resonance method in the temperature interval between room temperature and 1300 °C. Elastic constants at such high temperatures are needed to model the mechanical behavior of blade material during manufacturing (hot isostatic pressing) as well as during technical accidents which may happen in service (overheating). High reliability of the results was achieved using specimens of different crystallographic orientations, exciting various vibration modes as well as precise measurement of the material density and thermal Expansion required for modeling the resonance frequencies by finite element method. Combining the results measured in this work and literature data the elastic constants of the gamma and gamma' phases were predicted. This prediction was supported by measurement of the temperature dependence of the gamma'fraction. All data obtained in this work are given in numerical or analytical forms and can be easily used for different scientific and engineering calculations. KW - Nickel-base superalloys KW - Single-crystals KW - Characterization KW - Elastic constants PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520972 DO - https://doi.org/10.3390/cryst11020152 VL - 11 IS - 2 SP - 152 PB - MDPI AN - OPUS4-52097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -