TY - CONF A1 - Voigt, Marieke A1 - Hirsch, T. A1 - Meng, Birgit A1 - Stephan, D. T1 - Hydration and crystallization of Portland cement at 100 C N2 - For the construction of hot water storage tanks, ultra high performance concrete proofed to be a suitable building material to ensure water tightness. Common storage tanks build with concrete are designed to endure temperatures up to 90 °C. To increase the energy efficiency however, modern tanks need to withstand temperatures above 100 °C. With increasing temperature and correlating water vapor pressures, the cement must meet new requirements. Thermodynamic modelling is a promising tool for predicting the phase stabilities of minerals in the cement within these temperature and pressure ranges (T/P). Thus, mixture designs can be investigated and optimized with regard to the expected mineral phases in selected T/P-ranges. Additionally, predictions of the long-term material behavior can be derived from thermodynamic data and subsequently the experimental effort can be reduced notably. On the other hand, validation of predictions is needed. The base for the thermodynamic model is a thermodynamic equilibrium and thus, the experimental data for validation should approach the presumed conditions of the equilibrium. This study investigates variable experimental conditions for the hydration of Portland cement at 100 °C to reach a sufficiently progressed development of the phase composition. In case of Portland cement, the highest degree of hydration achievable within a reasonable time span is the most significant parameter. Therefore, Portland cement pastes with w/c ratios from 0.4 to 0.6 and dwell times up to three weeks were examined with powder X-ray diffraction to identify mineral phase changes. At 100 °C and high humidity, Portland cement paste shows the expected mineral phases like portlandite, katoite, and remaining clinker phases. The cement pastes with high water content and long dwell time seem to have the highest degree of hydration, even though the AFm phases stabilize with increasing w/c ratio. A dwell time of two weeks and a w/c ratio of 0.5 was found to provide the mineral composition with the highest degree of hydration including the major phase transitions. T2 - 4th International Conference on the Chemistry of Construction Materials (ICCCM) CY - Karlsruhe, Germany DA - 26.09.2022 KW - Hydration KW - High temperature KW - Portland cement PY - 2022 AN - OPUS4-56866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voigt, Marieke A1 - Gardei, Andre A1 - Meng, Birgit T1 - The adaption of the set-up for gas permeability measurements for ultra-high performance concrete N2 - In the framework of this project, a steam pressure vessel was to be developed from ultra-high perfor-mance concrete (UHPC) to withstand process temperatures of 200 °C and the respective steam pressure of 15,5 bar. To guarantee the long-term water vapour tightness of the system, the permeability of two UHPC mixtures were tested after long-term cyclic autoclaving. As UPHC shows a high density and therefore low permeability, measurements after the RILEM-Recommendation (TC 116-PCD) reached their detection limit. Therefore, the measurement set-up was adapted to measure the permeability of highly dense UHPC more reliably and quickly. This adaption includes measurements in a higher pres-sure range, the change of sample size thickness and the usage of Ar as a medium compared with the RILEM Recommendation. Additionally, the system was equipped with two pressure sensors and Ar-flowmeters to guarantee a continuous record of the experimental parameters. The new system was tested and evaluated by comparing measurements with the RILEM recommended system. Preliminary results show that the adapted system is capable to provide efficient and reliable results of concrete with low permeability. T2 - 14th fib PhD Symposium in Civil Engineering CY - Rome, Italy DA - 05.09.2022 KW - Hydration KW - High temperature KW - Portland cement PY - 2022 AN - OPUS4-56859 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Grelle, Tobias A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Wolff, Dietmar T1 - Three-dimensional thermal expansion of neat and irradiated (U)HMWPE materials at elevated temperatures JF - Polymer Testing N2 - The thermal expansion of polymeric parts can be an issue in many applications where the available space is limited, or exact dimensions of the part are required. For this study, a device was designed and built that allowed measuring the thermal expansion simultaneously in all three spatial directions on cubic samples with real-scale dimensions (78 mm edge length). The results are shown between 25 °C and 125 °C for two PE materials, one HMWPE and one tempered UHMWPE, for non-irradiated samples as well as cubes that have been irradiated with 100 and 400 kGy. The results measured with the new device were very similar to those measured with conventional thermo-mechanical analysis equipment and to literature data of UHMWPE. The HMWPE material shows a much larger thermal expansion coefficient in one direction compared to the other two directions during the first heating due to frozen stresses from the pressing step during material manufacturing. These stresses are mostly released by the expansion during the first heating, so that the expansion during the second heating is more uniform. The overall volumetric expansion is the same for both heating runs. By contrast, the tempered UHMWPE material shows no significant difference between first and second heating run, as the stresses from processing could already relax in the tempering step. The irradiation treatment does not affect the values significantly for the given test set-up. KW - Lupolen KW - Ultra high molecular weight polyethylene KW - GUR KW - Coefficient of thermal expansion KW - High temperature PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563987 DO - https://doi.org/10.1016/j.polymertesting.2022.107841 SN - 0142-9418 VL - 117 SP - 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-56398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shapovalov, O. A1 - Heckel, Thomas A1 - Gaal, Mate A1 - Weiß, S. T1 - External Acoustical Damping on a Metallic Angle Wedge in a High Temperature Resistant Ultrasonic Probe JF - Acoustics Australia N2 - Ultrasonic probes for high-temperature applications are provided with metallic wedges, which can withstand the contact with the high temperature of the inspected structure. The ultrasonic signal travels within the wedge and gets reflected from its boundaries, causing interference signals called “ghost echoes”. The current work presents an investigation of the additional damping effect provided by porous sintered metal plates applied onto the surface of the wedge. In particular, the study evaluates the effect of damping plate thickness on the interference signal level at different transmission frequencies. Damping plates made of sintered metal SIKA-R 15 AX were attached to a wedge prototype made of steel 1.4301. The study revealed, that the most effective thickness of damping plates in the selected frequency interval of 1 to 4 MHz is equal to 4 mm. The evaluation of the interference signal has shown that the application of such damping plates to the wedge surface contributes to an additional attenuation of an interference signal of 10 to 30 dB after 500 μs of signal propagation. KW - Ultrasonic testing KW - High temperature KW - Acoustical damping KW - Angle wedge KW - Ultrasonic probe PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553920 DO - https://doi.org/10.1007/s40857-022-00270-9 SN - 0814-6039 SP - 1 EP - 11 PB - Springer AN - OPUS4-55392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Novel insights into high temperature corrosion phenomena by advanced X-ray methods N2 - A variety of materials of technological interest change their properties through contact with reactive media. Solid-gas reactions lead to a variety of reaction products on the surfaces and internal interfaces. The observation of nucleation and growth processes in the environment where they occur (in situ) from a chemical-structural perspective is especially challenging for aggressive atmospheres. The talk presents innovative approaches to study corrosion mechanisms using advanced X-ray methods. Using energy dispersive X-ray diffraction and X-ray absorption spectroscopy in different tailor made environmental reaction chambers, valuable insights into high temperature oxidation and sulfidation processes were gained. Fe-based alloys were exposed to hot and reactive atmospheres containing gases like SO2, H2O and O2 at 650°C. During the gas exposure the tailor made reaction chambers were connected to a high energy diffraction end station at the synchrotron. The crystallization and growth of oxide and sulfide reaction products at the alloy surfaces were monitored by collecting full diffraction pattern every minute. Careful examination of shape and intensity of phase-specific reflections enabled to a detailed view on growth kinetics. These studies showed, oxides are the first phases occurring immediately after experimental start. As soon as reactive gas media enter the chamber, the conditions change and different reaction products, such as sulfides start to grow. A comparison of different gas environments applied, illustrated the differences in the type of reaction products. The in situ observation of high temperature material degradation by corrosion made it possible to study the contribution of phases, which are not stable at room temperature. For instance, wuestite (Fe1-xO), was frequently observed at high temperatures in humid gases on Fe with 2 wt.% and 9 wt.% chromium, but not at room temperature. The strength of the occurrence of this phase additionally explains why, despite a higher Cr content, ferritic alloys with 9 wt.% Cr in a challenging atmosphere prevent the intrinsic formation of protective layers. The in situ observations were supplemented by careful considerations of thermodynamic boundary conditions and detailed post characterization by classical metallographic analysis. Additionally, the structure and chemistry of the dominant oxide layers were evaluated using X-ray absorption near edge structure spectroscopy. The talk will give an overview about chances and challenges for studying high temperature corrosion phenomena by advanced X-ray methods. T2 - MRS Spring Meeting CT08.02.01 CY - Online Meeting DA - 18.04.2021 KW - XRD KW - Spectroscopy KW - Corrosion KW - High temperature KW - In-situ PY - 2021 AN - OPUS4-52486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Puthiyaveettil, N. A1 - Thomas, K. R. A1 - Myrach, Philipp A1 - Ziegler, Mathias A1 - Rajagopal, P. A1 - Balasubramaniamam, K. T1 - Defect detection in steel bars up to 600 °C using laser line thermography JF - Infrared Physics & Technology N2 - Crack detection in steel bars at high surface temperatures is a critical problem in any manufacturing industry. Surface breaking cracks are the major problems during the billet casting. Many NDT techniques are proven its capability in crack detection at room temperature. Here, we are demonstrating the possibility of exposure of cracks using laser line thermography at higher surface temperatures (up to 600 °C). A continuous-wave (CW) laser is used to excite the sample kept at higher surface temperatures. The temperature distribution over the sample due to the laser line scanning is captured using a temperature calibrated infrared (IR) thermal camera. The response of the sample temperature in crack detection is investigated using a validated FE model. The impact of the oxide layer in crack detection is investigated by using two types of samples; one without any oxide layer and the second is with the oxide layer. The influence of laser power in the detection of defects at high temperatures is studied. 3D numerical models were developed for the cases; when the sample is with oxide layer and without any oxide layer for a better understanding of physics. The surface temperature rise due to laser heating is higher for the scaled sample compared to the no-scale sample. The presence of the oxide layer above the parent metal will reduce the reflectivity of the surface. Lower reflectivity will lead to increased absorption of incident energy so that the surface temperature rise will be higher than the surface with no scale. Thermal contrast linearly depends on laser power, which means higher laser power will increase the defect detectability even at a higher surface temperature. KW - Laser thermography KW - High temperature KW - Modeling KW - Surface cracks KW - Non-destructive testing PY - 2020 DO - https://doi.org/10.1016/j.infrared.2020.103565 SN - 1350-4495 VL - 111 SP - 103565 PB - Elsevier B.V. AN - OPUS4-51573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Huismann, Sven A1 - Zeiml, M. A1 - Korzen, Manfred A1 - Millard, A. ED - Millard, A. ED - Pimienta, P. T1 - Engineering Modelling T2 - Modelling of Concrete Behaviour at High Temperature N2 - This chapter presents the most commonly used approach to analyse the thermo-mechanical behaviour of concrete structures subjected to high temperatures as in the case of fire loading. Prescriptions of the Eurocode are detailed for the thermal as well as the mechanical analysis. Finally, recommendations from two national (Austrian and German) guidelines give some improvements for Underground infrastructure. KW - Concrete KW - High temperature KW - Stress-strain-relation PY - 2019 SN - 978-3-030-11995-9 DO - https://doi.org/10.1007/978-3-030-11995-9 SN - 2213-204X SN - 2213-2031 SP - 15 EP - 25 PB - Springer CY - Cham, Switzerland AN - OPUS4-51186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Meftah, F. A1 - Pesavento, F. A1 - Davie, C. A1 - Dal Pont, S. A1 - Zeiml, M. A1 - Korzen, Manfred A1 - Millard, A. ED - Millard, A. ED - Pimienta, P. T1 - Advanced Modelling T2 - Modelling of Concrete Behaviour at High Temperature N2 - In this chapter, advanced models based on a General thermo-Hydro-Mechanical (THCM) Framework are considered. In These approaches, the concrete is considered as a porous medium, the pores of which are partly filled by gas (a mixture of air and vapour) and water. KW - Concrete KW - High temperature KW - Stress-strain-relation PY - 2019 SN - 978-3-030-11994-2 SN - 978-3-030-11995-9 DO - https://doi.org/10.1007/978-3-030-11995-9 SN - 2213-204X SN - 2213-2031 SP - 27 EP - 65 PB - Springer CY - Cham, Switzerland AN - OPUS4-50174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koclega, Damian A1 - Radziszewska, A. A1 - Dymek, S. A1 - Kranzmann, Axel T1 - Corrosion behaviour of Ni-Cr-Mo-W coatings in environments containing sulfur N2 - The ferritic steel 13CrMo4-5 due to good properties with relation to attractive price is frequently use in power plants industry. According EN10028-2 this steel can be used up to 570 °C because of its creep behavior but its corrosion resistance limits the use frequently to lower temperatures, depending on gas temperature and slag formation. The corrosion test were performed in environment containing mixture of gases like: O2, COx, SOx and ashes, with elements e.g. Na, Cl, Ca, Si, C, Fe, Al. Exposure time was respectively 240 h, 1000 h and 4500 h in temperature 600 °C. The oxide scale on the 13CrMo4-5 steel was significant thicker than for In686 coating and the difference increase according for longer exposure time. The microstructure, chemical and phase composition of the oxide scales were investigated by means of a light microscope, the electron scanning and transmission microscopes (SEM,TEM) equipped with the EDS detectors. T2 - Gordon Research Conference CY - New London, New Hampshire, USA DA - 21.07.2019 KW - High temperature KW - Corrosion resistance KW - Laser cladding KW - Inconel 686 KW - Aggressive environment PY - 2019 AN - OPUS4-49358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Unravelling high temperature oxidation phenomena by in situ x-ray techniques N2 - Unravelling high temperature oxidation phenomena by in situ x-ray techniques. A multi techqnique approach to study high temperature gas corrosion is presented. T2 - Gordon Research Conference on High Temperature Corrosion CY - New London, NH, USA DA - 20.07.2019 KW - Corrosion KW - High temperature KW - Diffraction KW - Spectroscopy PY - 2019 AN - OPUS4-48772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Pistol, Klaus A1 - Huismann, S. A1 - Diederichs, U. A1 - Pimienta, P. A1 - Jumppanen, U.M. A1 - Mindeguia, J.C. T1 - Stress-strain-relation, compressive strength and modulus of elasticity T2 - Physical Properties and Behavour of High-Performance Concrete at High Temperature N2 - This chapter report the most recent experimental results on mechanical behaviour at high temperature of high-performance concretes. After a short introduction, subsection 5.2 describes the main testing methods that were used in the analysed studies. Sub-section 5.3 collects and compares; the temperature-dependency of the compressive strength and modulus of elastici1ty of many experimental studies. The influence of parameters such as the initial compressive strength, the type of aggregate, the presence of additions, the W/C ratio, the moishrre content and the way the mechanical test was performed is analysed. Sub-section 5.4 presents the experimental results obtained under a constant temperature, i.e. creep tests at high temperature. Sub-section 5.5 presents experimental results obtained under increasing temperahrre. These results allow assessing the free thennal strain of concrete (when no mechanical load is applied) and the so-called "transient the1mal strain". Finally, subsection 5.6 collects and analyses the few results conceming the temperature-dependency of the tensile strength of high-perfo1mance concretes. KW - Stress-strain-relation KW - High temperature PY - 2019 SN - 978-3-319-95431-8 SN - 978-3-319-95432-5 SN - 2213-204X SN - 2213-2031 SP - 89 EP - 105 PB - Springer CY - Swizerland AN - OPUS4-47212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nofz, Marianne T1 - High temperature coatings (Book review) T2 - Materials and Corrosion 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 DO - 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 - CONF A1 - Pohl, Christoph A1 - Unger, Jörg F. T1 - Modeling thermomechanical damage mechanisms of concrete N2 - Compressive strength of concrete is highly temperature dependent. Using experimentally obtained relations as input for numerical simulations is problematic. A more accurate and reliable material model results from taking the coupling between thermal and mechanical behaviour into account. In this contribution, a coupled finite element solution on mesoscale geomtries is shown to exhibit a loss in compressive strength at higher temperatures. This is purely a result of the incompatible expansion of mortar matrix and aggregates, with no explicit temperature dependency of the employed constitutive models. T2 - VII International Conference on Coupled Problems in Science and Engineering CY - Rhodos, Greece DA - 12.06.2017 KW - Compressive strength of concrete KW - High temperature KW - Finite elements KW - Mesoscale KW - Thermomechanics PY - 2017 AN - OPUS4-40672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruno, Giovanni A1 - Vogel, S. C. T1 - Simultaneous determination of high-temperature crystal structure and texture of synthetic porous cordierite JF - Journal of Applied of Crystallography N2 - The evolution of the crystal structure and crystallographic texture of porous synthetic cordierite was studied by in situ high-temperature neutron diffraction up to 1373 K, providing the first in situ high-temperature texture measurement of this technologically important material. It was observed that the Crystal texture slightly weakens with increasing temperature, concurrently with subtle changes in the crystal structure. These changes are in agreement with previous work, leading the authors to the conclusion that high-temperature Neutron diffraction allows reliable crystallographic characterization of materials with moderate texture. It was also observed that structural changes occur at about the glass transition temperature of the cordierite glass (between 973 and 1073 K). Crystal structure refinements were conducted with and without quantitative texture analysis being part of the Rietveld refinement, and a critical comparison of the results is presented, contributing to the sparse body of literature on combined texture and crystal structure refinements. KW - Synthetic extruded cordierite KW - Crystal texture KW - Neutron diffraction KW - High temperature KW - Atomic displacement parameters KW - Atomic distances PY - 2017 DO - https://doi.org/10.1107/S160057671700406X SN - 1600-5767 VL - 50 IS - Part 3 SP - 749 EP - 762 PB - IUCR CY - New York AN - OPUS4-40584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Armatys, Kamila A1 - Miller, M. T1 - Knudsen effusion mass spectrometry studies on metal halides performed in 1990-2014 JF - The Pharmaceutical and Chemical Journal N2 - Abstract Investigations on metal halide systems carried out by Knudsen effusion mass spectrometry in the period 1990-2014 are reviewed in the present paper.163 original papers were published focused on metal halides showing still considerable activity in this area. The fundamentals of the Knudsen effusion mass spectrometry method and thermodynamic background of the investigation are briefly reported. Data to the system studied, temperature ranges, Knudsen cell materials, vapor species identified in the equilibrium vapors and the thermodynamic properties obtained in the study are presented. The important issues of metal halide vaporization studies are briefly discussed and commented. The studies of the vaporization of metal halogens by Knudsen effusion mass spectrometry aimed firstly atthe determination of gaseous complexes species in the vapor and determination of its thermodynamic data like sublimation enthalpy etc. and secondly at the determination of negative ions formation and various ion-molecule equilibria reactions of metal halide systems. Many of the studied materials have a crucial role for modern technologies, for example metal halide lamps, hot corrosion caused by halide salts, phosphorus recovery technologies or gas assisted separation of lanthanides. The investigation of such systems gives information on mechanisms of vaporization, volatility of the systems under various conditions (temperature, pressure etc.), reactivity, thermal stability, resistance etc. that could be further applied for various calculations and to predict the behavior of various components under various technological aspects. KW - Metal halides KW - Knudsen Effusion Mass Spectrometry (KEMS) KW - HTMS KW - Thermochemistry KW - High temperature KW - Vaporization PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-357126 SN - 2349-7092 VL - 3 IS - 1 SP - 68 EP - 93 PB - The Pharmaceutical and Chemical Journal CY - Kundlawala, India AN - OPUS4-35712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, A. A1 - Wolthusen, Helmut A1 - Zastrow, Philip A1 - Kranzmann, Axel ED - Jha, A. ED - Wang, C. ED - Neelameggham, N.R. ED - Guillen, D.P. ED - Li, L. ED - Belt, C.K. ED - Kirchain, R. ED - Spangenberger, J.S. ED - Johnson, F. ED - Gomes, A.J. ED - Pandey, A. ED - Hosemann, P. T1 - Evaluation of heat treatment performance of potential pipe steels in CCS-environment T2 - Energy Technology 2015: Carbon Dioxide Management and Other Technologies N2 - To resist the corrosive geothermal environment during carbon capture and storage CCS -such as: heat, pressure, salinity of the aquifer, CO2-partial pressure, properties of pipe steels-require certain specification. For evaluation samples of differently heat treated high alloyed stainless injection-pipe steels AISI 420 X46Cr13, AISI 420J X20Cr13 as well as X5CrNiCuNb16–4 AISI 630 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h up to 8000 h in a CO2-saturated synthetic aquifer environment similar to a possible geological situation in the northern German Basin. Corrosion rates and scale growth are lowest after long term exposure for steels hardened and tempered at 600 °C to 670 °C and pits -indicating local corrosion- decrease in diameter but increase in number as a function of carbon content of the steel. Martensitic microstructure is preferred with respect to these particular conditions. KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - High temperature KW - High pressure PY - 2015 SN - 978-1-119-08240-8 DO - https://doi.org/10.1002/9781119093220.ch2 SP - 15 EP - 22 PB - Wiley AN - OPUS4-34717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berger, L.-M. A1 - Stahr, C.C. A1 - Saaro, S. A1 - Thiele, S. A1 - Woydt, Mathias A1 - Kelling, Norbert T1 - High temperature tribology up to 7.5 m/s of thermally sprayed coatings of the TiO2-Cr2O3 system and (Ti,Mo)(C,N)-Ni(Co) T2 - 49. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen T2 - 49. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Deutschland DA - 2008-09-22 KW - Thermal spraying KW - Dry sliding KW - High temperature KW - APS KW - HVOF KW - WC KW - Ni KW - Cermet KW - (Ti,Mo)(C,N) KW - Dry friction PY - 2008 SN - 978-3-00-025676-9 VL - I SP - 1/1 EP - 1/15 AN - OPUS4-31749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Triboactive materials for 'zero wear' under dry sliding up to 800°C and mixed lubrication, dry oscillation and thin film coatings under slip-rolling T2 - 16th International colloquium tribology - Lubricants, materials and lubrication engineering T2 - 16th International colloquium tribology - Lubricants, materials and lubrication engineering CY - Stuttgart/Ostfildern, Germany DA - 2008-01-15 KW - Wear KW - Fretting KW - Contact geometry crossed cylinders KW - Friction KW - Thermal spraying KW - BAM test KW - SRV KW - Oscillation KW - Triboactive KW - Coatings KW - APS KW - HVOF KW - (Ti,Mo)(C,N) KW - Tin-2Cr2O2n-1 KW - Magnéli phases KW - DLC KW - THC KW - ta.C KW - High temperature KW - Foil bearings KW - Dry friction KW - Air KW - Mixed and boundary lubrication KW - Slip-rolling PY - 2008 SP - Paper 00_06_Woydt_Plenar, 1 EP - 15 AN - OPUS4-31737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pereira, F. A1 - Pistol, Klaus A1 - Korzen, Manfred A1 - Weise, Frank A1 - Pimienta, P. A1 - Carré, H. A1 - Huismann, Sven ED - Koenders, E.A.B. ED - Dehn, F. T1 - Monitoring of fire damage processes in concrete by pore pressure and acoustic emission measurements T2 - 2nd International RILEM workshop on concrete spalling due to fire exposure (Proceedings) N2 - This paper presents the combined use of acoustic emission (AE), gas pore pressure and temperature measurements (PT). The simultaneous application of both techniques represents a new methodology in the context of fire spalling and contributes to a better understanding of the mechanisms of fire spalling, particular with regard to the interaction of micro cracking and pore pressure evolution. The study presents fire tests on normal strength concrete specimens with and without reinforcement at ISO Standard fire and at hydrocarbon (HC) fire. Supported by AE-analysis, it can be shown that due to the higher heating rate of the HC-fire in comparison to the ISO Standard fire the damage processes inside the concrete during the exposure are increased combined with augmenting the concrete permeability. As a consequence lower pore pressures were measured. However, despite the lower pore pressures, explosive spalling was observed. T2 - 2nd International RILEM workshop on concrete spalling due to fire exposure CY - Delft, The Netherlands DA - 05.10.2011 KW - Ordinary concrete KW - High temperature KW - Gas pore pressure KW - Acoustic emission KW - Spalling PY - 2011 SN - 978-2-35158-118-6 SP - 69 EP - 77 PB - RILEM Publications AN - OPUS4-24818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard A1 - Owen, J. ED - Bell, R. ED - Merati, A. ED - M. Nganbe, ED - Tyson, B. ED - Wang, X. T1 - Creep damage by multiple cavity growth controlled by grain boundary diffusion T2 - ICF12 - 12th International conference on fracture (Proceedings) T2 - ICF12 - 12th International Conference on Fracture CY - Ottawa, Canada DA - 2009-07-12 KW - Grain boundary cavitation KW - Hochtemperatur KW - Kriechen KW - Schädigung KW - Korngrenzenporosität KW - High temperature KW - Creep KW - Damage PY - 2009 SP - 1 EP - 10 AN - OPUS4-20623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Hartelt, Manfred A1 - Weihnacht, V. T1 - Influence of counterbody material on wear of ta-C coatings under fretting conditions at elevated temperatures JF - Wear N2 - The high temperature tribological performance of tetrahedral amorphous carbon coatings has been analyzed at elevated temperatures up to 250 °C in air against three different counterbody materials-steel 100Cr6, a-alumina and silicon nitride. The results show that the counterbody material influences the friction and wear behavior and therefore coating life time strongly. This effect is well known for these coatings at room temperature under dry environmental conditions, equivalent to conditions above 100 °C when water molecules desorb from the surface. However, the sharp difference in tribological performance between silicon nitride on the one hand and alumina and steel on the other hand cannot be understood in this context. Analyzing the friction behavior during the running-in phase, it is evident that only alumina and steel form a stable interface with constant low friction and relatively low wear rates. Silicon nitride forms an unstable interface with fluctuating COF and relatively high wear rates due to its own inherent tendency to tribo-oxidation. KW - Fretting KW - Hard carbon coatings KW - ta-C KW - High temperature KW - Counterbody influence PY - 2009 DO - https://doi.org/10.1016/j.wear.2009.08.041 SN - 0043-1648 VL - 267 IS - 12 SP - 2208 EP - 2215 PB - Elsevier CY - Amsterdam AN - OPUS4-20344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mc Hugh, Jarlath A1 - Döring, Joachim A1 - Stark, Wolfgang A1 - Guey, J. L. T1 - Relationship between the Mechanical and Ultrasound Properties of Polymer Materials T2 - 9th European Conference on NDT T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Ultrasound KW - DMA KW - Epoxy KW - Modulus KW - tan delta KW - High temperature PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 9(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Levkovitch, Vladislav A1 - Sievert, Rainer A1 - Svendsen, Robert F. T1 - Simulation of deformation and lifetime behavior of a fcc single crystal superalloy at high temperature under low-cycle fatigue loading JF - International Journal of Fatigue N2 - This work deals with the formulation of a three-dimensional crystallographic time-incremental lifetime rule for face-centered cubic (fcc) single crystals used for gas-turbine blade applications. The damage contribution rate of each slip system to the total damage is governed by the current values of the resolved shear stress and the slip rate on the corresponding slip system. The damage rule is combined with a crystallographic viscoplastic deformation model. For the nickel-base single-crystal superalloy CMSX4 at 950 °C, various strain- and stress-controlled uniaxial cyclic tests with and without hold-times can be described for different crystal orientations by one set of material parameters. For verification, simulation results for a single-crystal specimen with a notch have been compared with corresponding experimental results. The predicted lifetime is within the factor of two of the measured one. KW - Single crystal KW - High temperature KW - Viscoplastic constitutive model KW - Lifetime rule KW - Low-cycle fatigue KW - Superalloy PY - 2006 DO - https://doi.org/10.1016/j.ijfatigue.2005.12.006 SN - 0142-1123 VL - 28 IS - 12 SP - 1791 EP - 1802 PB - Elsevier CY - Oxford AN - OPUS4-13198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fedelich, Bernard A1 - Kiyak, Yusuf A1 - May, Thomas A1 - Pfennig, Anja ED - Gdoutos, E. T1 - Simulation of crack growth under low cycle fatigue at high temperature in a single crystal superalloy T2 - Fracture of nano and engineering materials and structures T2 - 16th European Conference of Fracture "Fracture of Nano and Engineering Materials and Structures" CY - Alexandroupolis, Greece DA - 2006-07-03 KW - Simulation KW - Experiment KW - Crack growth KW - Low cycle fatigue KW - High temperature KW - Single crystal KW - Superalloy KW - Oxidation PY - 2006 SN - 1-402-04971-4 IS - 900_tra SP - 8 pages PB - Springer CY - Dordrecht AN - OPUS4-12556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Chen, W. A1 - Darowski, N. A1 - Zizak, I. A1 - Schumacher, G. A1 - Klingelhöffer, Hellmuth A1 - Wanderka, N. A1 - Neumann, W. ED - Chandra, T. ED - Torralba, Jose M. ED - Sakai, T. T1 - Measurement of Gamma/Gamma' Lattice Mismatch in Creep Deformed SIngle Crystal Superalloy SC16 Using Synchrotron X-Radiation T2 - THERMEC 2003 T2 - International Conference on Processing & Manufacturing of Advanced Materials CY - Leganés, Spain DA - 2003-07-07 KW - Superalloy KW - Lattice mismatch KW - High temperature KW - Creep deformed PY - 2003 SN - 0-87849-919-9 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum IS - 426-432/5 SP - 4555 EP - 4560 PB - Trans Tech Publ. CY - Uetikon-Zürich AN - OPUS4-2790 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias T1 - Tribological characteristics of polycrystalline Magnéli-type titanium dioxides JF - Tribology letters N2 - The results presented in this paper have clarified experimentally, that titania-based Magnéli-phases (Ti4O7/Ti5O9 and Ti6O11) with (121)-shear planes exhibit more anti-wear properties than lubricious (low-frictional) properties. The results for dry sliding indicate that the coefficients of friction lie in the range of 0.1–0.6 depending on sliding speed and ambient temperature. The COF decreased with increasing temperature (T= 22–800°C) and increasing sliding speed (?= 1-6 m/s). The dry sliding wear rate was lowest for the Al2O3 at 1 m/s at 800°C with values of 1.7 × 10-8 and 6.4 × 10-8 mm3/N m, comparable to boundary/mixed lubrication, associated with a high dry frictional power loss of 30 W/mm2. The running-in wear length and, more important, the wear rate decreased under oscillating sliding tests with increasing relative humidity. The contact pressure for high-/low-wear transition increased under oscillating sliding tests with increasing relative humidity. At room temperature and a relative humidity of 100% the steady-state wear rate under dry oscillating sliding for the couple Al2O3/Ti4O7–Ti5O9 was lower than 2 × 10-7 mm3/N m and therefore inferior to the resolution of the continuous wear measurement sensor. TEM of wear tracks from oscillating sliding revealed at room temperature a work-hardening as mechanism to explain the running-in behavior and the high wear resistance. The hydroxylation of titania surfaces favours the high-/low-wear transition. KW - Magnéli-phases KW - Shear planes KW - Planar defects KW - Ceramics KW - Dry friction KW - High temperature KW - Titania KW - Wear KW - Work-hardening KW - TEM KW - Humidity PY - 2000 DO - https://doi.org/10.1023/A:1019170831371 SN - 1023-8883 SN - 1573-2711 VL - 8 SP - 117 EP - 130 PB - Springer Science Business Media B.V. CY - Dordrecht AN - OPUS4-2443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Skopp, André A1 - Woydt, Mathias A1 - Habig, Karl-Heinz T1 - Tribological behavior of silicon nitride materials under unlubricated sliding between 22°C and 1000°C JF - Wear KW - Silicon nitride KW - Wear maps KW - High temperature KW - Tribology KW - T-maps KW - Ceramics composites PY - 1995 SN - 0043-1648 VL - 181-183 SP - 571 EP - 580 PB - Elsevier CY - Amsterdam AN - OPUS4-2417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Yarim, Rasim A1 - Wäsche, Rolf A1 - Woydt, Mathias ED - Franek, F. T1 - Wear Behaviour of SiC-TiC-TiB2 Ceramic Composites Sliding against SiC up to 800°C and 2m/s T2 - Tribology 2001 T2 - 2nd World Tribology Congress ; 2nd WTC 2001 CY - Vienna, Austria DA - 2001-09-03 KW - Dry sliding KW - Tribochemistry KW - Silicon carbide KW - Titanium carbide KW - Titanium boride KW - High temperature KW - Ceramic composites PY - 2001 SN - 3-901657-07-X SP - 1(?) EP - 4(?) PB - ÖTG CY - Wien AN - OPUS4-1438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -