TY - CONF A1 - Theiler, Géraldine T1 - Sliding behaviour of polymer materials in hydrogen N2 - This lecture deals with the sliding behaviour of polymer materials in hydrogen environment. After a short introduction of the hydrogen activities at BAM, the tribological performances of polymer materials in gaseous hydrogen are presented and compared with air and vacuum environment. The second part focusses on the influence of the counterface materials in hydrogen. Finally, the last section is dedicated to experiments liquid hydrogen. T2 - Invited lecture, TRIBOS+ program at Lulea University of Technology CY - Lulea, Sweden DA - 30.06.2021 KW - Polymers KW - Hydrogen KW - Friction KW - Wear PY - 2021 AN - OPUS4-53708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine T1 - On the tribological behaviour of polymer composites in vacuum N2 - This lecture deals with the sliding behaviour of polymer composites in vacuum environment. At first, the effect of the polymer matrix and solid lubricants such as graphite and MoS2 are presented. The second part focusses on the influence of the residual pressure with experimental results obtained in high and ultrahigh vacuum. T2 - Invited lecture, TRIBOS+ program at Lulea University of Technology CY - Lulea, Sweden DA - 29.06.2021 KW - Polymers KW - Vacuum KW - Friction KW - Wear PY - 2021 AN - OPUS4-53710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Gradt, Thomas T1 - Benchmarking of polymer materials for tribological applications in hydrogen N2 - The focus of this study is to evaluate of hydrogen on the friction and wear behavior of a wide range of polymer materials. Thereby, the tribological performance of filled and unfilled polymers from different suppliers were compared at room temperature in air and hydrogen gas (H2) as well as in liquid hydrogen at -253°C (LH2). T2 - 62. Tribologie-Fachtagung der Gesellschaft für Tribologie e. V. CY - Online meeting DA - 27.09.2021 KW - Polymers KW - Hydrogen KW - Friction KW - Wear PY - 2021 AN - OPUS4-53700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine A1 - Gradt, Thomas T1 - Tribology of polymeric materials in gaseous and liquid hydrogen N2 - This presentation gives an overview of the tribological behaviour of polymeric materials in gaseous and luquid hydrogen. T2 - HYDROGENIUS-BAM Joint Hydrogen Symposium CY - Online meeting DA - 06.07.2021 KW - Polymers KW - Hydrogen KW - Friction KW - Wear PY - 2021 AN - OPUS4-53701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Géraldine T1 - Friction and wear of polymer materials at cryogenic temperatures N2 - This lecture deals with the friction and wear of polymeric materials at cryogenic temperatures. The first part is dedicated to the low temperature properties of polymers and cryogenic environment as well as an introduction to cryotribology and friction models. The second part presents some experimental results, focusing on the effect of polymer composition, cryogenic media and stick-slip behaviour. T2 - Invited lecture, TRIBOS+ program at Lulea University of Technology CY - Lulea, Sweden DA - 29.06.2021 KW - Polymers KW - Cryogenic temperature KW - Friction KW - Wear PY - 2021 AN - OPUS4-53706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Spaltmann, Dirk A1 - Ayerdi, J. A1 - Slachciak, Nadine A1 - Llavori, I. A1 - Zabala, A. A1 - Aginagalde, A. A1 - Bonse, Jörn T1 - Tribological performance of FS-laser-induced periodic surface structures on titanium alloy against different counter-body materials using a ZDDP lubricant additive N2 - In this study the so-called laser-induced periodic surface structures (LIPSS, ripples) were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond (fs) laser. The tribological performance of the resulting surfaces was qualified in linear reciprocating sliding tribological tests (RSTT) against balls made of different materials (100Cr6 steel/Al2O3/Si3N4) using different oil-based lubricants. The admixture of the additive 2-ethylhexylzinc-dithiophosphate (ZDDP) to a base oil containing only anti-oxidants and temperature stabilizers disclosed the synergy of the additive with the laser-oxidized nanostructures. This interplay between the laser-textured sample topography and the local chemistry in the tribological contact area reduces friction and wear. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Lubricant additives KW - Laser-induced periodic surface structures (LIPSS) KW - Wear KW - Friction PY - 2022 AN - OPUS4-55318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, M. A1 - Scholz, C. A1 - Burbank, J.-T. A1 - Spaltmann, Dirk T1 - Slip-rolling resistant steel alloys up to P0max = 3,920 MPa under lubricated conditions N2 - Downsizing (power-to-weight ratio) and higher speeds lead to a rise in Hertzian contact pressures in combination with an increase in surface or oil temperatures. Under such conditions, commonly used bearing steels, such as 100Cr6, reach their limits, creating a demand for alternative slip-rolling resistant steel alloys. The present work therefore compares the slip-rolling performance of various steel types with Maraging- and PM-type steel alloys in the Hertzian contact pressure range up to P0max of 4 GPa. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Steel KW - Alloy KW - Slip-rolling KW - Friction KW - Wear rate KW - Contact pressure PY - 2022 AN - OPUS4-55320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - Adjusting the functional properties of niobium carbide N2 - The process window and range of functional properties of NbC is wide, because micro-hardness, hot hardness, sliding wear resistance, elastic modulus and toughness can be tailored by the C/Nb ratio, because Nb4C3, Nb6C5 and other short and long range ordered phases occur in the region of homogeneity of NbCx (0,75≤ x ≤1.0) in the binary Phase diagram, and by the type of binder. Further improvements enable the addition of secondary carbides. Supporting results from literature and different grades with varying C/Nb ratio or binder types were illuminated. Thus, the NbC system offers to producers a wider process window, than WC. The impact of these tailored properties on sliding wear and cutting performance was illuminated by tribological and machining results. NbC can be synthesized by carbothermal conversion of Nb2O5 or be metallurgically grown in melts and leached out as coarse NbC cubes. NbC provides comparably lower friction in many relevant tribo-contacts and displays low wear. NbC and Nb2O5 have so far no REACH classification related to human toxicology and are not listed as substances of very high concern contrary to WO3 and Co3O4. T2 - 2016 International Conference on Powder Metallurgy & Particulate Materials CY - Boston, MA, USA DA - 05.06.2016 KW - Niobium carbide KW - NbC KW - Wear KW - Friction PY - 2016 AN - OPUS4-36497 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Tribological profile of hydraulic oils by using SRV N2 - Hydraulic oils are well established formulations developed around the pump test. Requirements for energy efficiency and also environmentally acceptable properties increased the demand for development. In the same time, system pressure and the used of servo-hydraulic vanes increased bringing specific formulations and materials to their limit. The vane pump is a key component in hydraulic systems and many other tribosystems in hydraulic circuits operate under different tribological operating conditions. The concept for ranking of hydraulic oils consists in using existing SRV-based ASTM test methods for evaluation of friction, wear and extreme pressure properties: D6425, friction and wear of oils (homologue to DIN 51834-2), D7421, extreme pressure properties of oils and D7755, wear volumes of ball and disks (homologue to DIN 51834-3. The tribological properties are assessed under the regime of mixed/boundary lubrication The SRV-based concept of tribological profile generates the wear volumes on two triboelements (specimen) and the extreme pressure properties as well as the evolution of friction in the wear and extreme pressure load step test. Thus, the benchmark and validation of hydraulic oils bear on a wider range of tribological properties. Round robin test results using the aforementioned testing concept will be shown. Another outcome is tribological set limits for inclusion in hydrau¬lic oil speci¬fications. T2 - Workshop on Tribological Testing of Components Using the SRV Test Machine CY - Bellevue, WA, USA DA - 30.06.2016 KW - Tribology KW - Hydraulic oils KW - SRV KW - ASTM test method KW - Friction KW - Wear PY - 2016 AN - OPUS4-36734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Patzer, G. A1 - Ebrecht, J. A1 - Woydt, Mathias T1 - New interpretation approaches for seizure load tests on the translatory oscillation tribometer (SRV) N2 - When looking in detail at analyses of the tribological load-carrying capacity of high-performance lubricants, it becomes apparent that the stop of the machine of an exclusive evaluation of the development of the coefficient of friction cannot provide any sufficient criteria for determining the occurrence of adhesive failure. This is due on the one hand to the increasing complexity of lubricant formulae and sophisticated additive packages, and on the other hand to the increasing frictional power capacity of modern drive and control concepts in the design of tribometers. For this reason, it is urgently needed to examine the adhesive processes and their detection in more detail with the help of appropriate tribological values and criteria. The evolution of the friction can be coupled with the stroke, contact resistant and/or noise emission. Besides from new criteria for adhesive failure, which were compiled by the work group for the relevant ISO, DIN and ASTM standards, this contribution discusses the inclusion of additional parameters. Among other things, it provides guidance on what evidence the continuous recording of the original coefficient of friction and position signals, the electrical contact resistance, temperature, noise emission, frictional power input of the machine and further derived parameters help to identify adhesive failures or events. T2 - Workshop on Tribological Testing of Components Using the SRV Test Machine CY - Bellevue, WA, USA DA - 30.06.2016 KW - Tribology KW - Friction KW - Translatory oscillation tribometer KW - Standards PY - 2016 AN - OPUS4-36735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -