TY - CONF A1 - Österle, Werner A1 - Müller, Urs A1 - Desplanques, Y. A1 - Bulthé, A.-L. A1 - Degallaix, G. A1 - Dmitriev, A.I. T1 - 3rd Body formation of two different brake pad materials designed for railway application T2 - 5th European Conference on Braking (JEF 2006), November 8-9, 2006, Lille, France (Proceedings) T2 - 5th European Conference on Braking (JEF 2006) CY - Lille, France DA - 2006-11-08 PY - 2006 SP - 107 EP - 115 AN - OPUS4-18699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Kloß, Heinz ED - Jayashree Bijwe, T1 - Basic considerations for the development of friction materials T2 - Proceedings of the IWAAFC-2, International Workshop on Advances in Asbestos-free Friction Composites T2 - IWAAFC-2, International Workshop on Advances in Asbestos-free Friction Composites CY - Delhi, India DA - 2008-02-07 PY - 2008 SP - 24 EP - 51 PB - Indian Academy of Sciences CY - Delhi, India AN - OPUS4-18701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Urban, Ingrid ED - Jayashree Bijwe, T1 - Characterization of up to date brake friction materials T2 - IWAAFC-1, International Workshop on Advances in Asbestos free Friction Composites, January 5-6, 2006, Delhi, India (Proceedings) T2 - IWAAFC-1, International Workshop on Advances in Asbestos free Friction Composites CY - Delhi, India DA - 2006-01-05 PY - 2006 SP - 21 EP - 35 CY - Delhi, India AN - OPUS4-18700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A.I. A1 - Smolin, A.Y. A1 - Psakhie, S.G. A1 - Österle, Werner A1 - Kloß, Heinz A1 - Popov, V.L. T1 - Computer modeling of local tribological contacts by the example of the automotive brake friction pair JF - Physical mesomechanics N2 - In the paper the method of discrete modeling (movable cellular automata method) and combined discrete-continuous description of the simulated medium are used to analyze processes occurring in the local contact of the automotive brake system. The characteristic size of the considered region is 1.5 ?m. The following contact situation is simulated: steel fiber coated by an iron oxide film as the brake pad and pearlitic steel also coated by an iron oxide layer as the disc. On the assumption of oxide layer wearing we simulate the iron oxide - iron oxide, iron oxide - metal and metal - metal contacts. The calculation results for the friction coefficient for various contact situations give quite adequate values. For example, for the oxide - oxide system the calculated coefficient is approximately equal to 0.4, while for the metal - metal contact the obtained value varies from 0.7 to 0.9. Analysis of a set of the obtained results allows concluding that oxide is formed more rapidly than the sliding layer, which in turn makes the friction coefficient value stabilized. PY - 2008 DO - https://doi.org/10.1016/j.physme.2008.03.008 SN - 1029-9599 VL - 11 IS - 1-2 SP - 73 EP - 84 PB - Inst. of Strength Physics and Materials Science SB RAS CY - Tomsk AN - OPUS4-18698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Kloß, Heinz T1 - Does ultra-mild wear play any role for dry friction applications, such as automotive braking? JF - Faraday discussions N2 - Nanostructured third body films and/or storage of wear debris at the surfaces of the first bodies are deemed as prerequisites of sliding under ultra-mild wear conditions. Since such features have been observed experimentally on brake pads and discs, attempts were undertaken to study their sliding behaviour by modelling on the nanoscopic scale with an approach based on Movable Cellular Automata (MCA). The model rendered the possibility to study the influence of different nanostructures systematically and to assess the impact of different brake pad ingredients on the sliding behaviour, velocity accommodation and friction force stabilization at a sliding contact. Besides providing a review on previously published modelling results, some additional new graphs enabling better visualization of dynamic processes are presented. Although ultra-mild wear conditions were considered to be essential for achieving the desired tribological properties, transitions to mesoscopic and macroscopic wear mechanisms were studied as well. The final conclusion is that ultra-mild wear and corresponding smooth sliding behaviour play an important role during automotive braking, even though temporarily and locally events of severe wear may cause friction instabilities, surface damage and release of coarse wear particles. KW - Dry friction KW - Ultra-mild wear KW - Third body KW - MCA-model KW - Simulation PY - 2012 DO - https://doi.org/10.1039/c2fd00117a SN - 1359-6640 SN - 1364-5498 VL - 156 IS - 0 SP - 159 EP - 171 PB - Soc. CY - Cambridge [u.a.] AN - OPUS4-26822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Hammouri, Basem A1 - Morales Guzman, Pablo Israel A1 - Wetzel, B. A1 - Yigit, D. A1 - Zhang, G. T1 - Exploring the beneficial role of tribofilms formed from an epoxy-based hybrid nanocomposite JF - Tribology International N2 - The composition and nanostructure of a beneficial tribofilm formed during sliding of a hybrid nanocomposite against steel were characterized comprehensively. A similar nanostructure was produced by high energy ball milling of the three identified tribofilm constituents: silica, hematite and graphite. By supplying powders to a pin-on-disc test it has been shown that neither silica, nor hematite, nor a mixture of both provide the low coefficient of friction (COF) observed for the hybrid composite. Only if graphite was blended with the oxides, the low COF was obtained. Thus, a film of finely dispersed stable inorganic wear products containing 15 vol% graphite provides low friction and wear in the considered case. KW - TEM KW - Nanocomposite KW - Tribofilm KW - Ball milling KW - Pin-on-disc test PY - 2015 DO - https://doi.org/10.1016/j.triboint.2015.03.006 SN - 0301-679X VL - 88 SP - 126 EP - 134 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-33035 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Giovannozzi, A. A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Rossi, A. A1 - Wetzel, B. A1 - Zhang, G. A1 - Dmitriev, A.I. T1 - Exploring the potential of Raman spectroscopy for the identification of silicone oil residue and wear scar characterization for the assessment of tribofilm functionality JF - Tribology International N2 - We applied a combination of Raman spectroscopy (RS) and cross-sectional transmission electron microscopy (X-TEM) to identify silicone oil residues and tribofilms at steel disc surfaces after tribological testing. Neither chemical cleaning nor mechanical removal of a 50 µm thick surface layer produced a surface without any silicone residue. Nevertheless, long-term tribological properties are not affected due to silicone degradation which has been proved by Raman spectroscopy. Excellent anti-wear and anti-friction properties of a nanocomposite at severe stressing conditions correlated with the formation of a silica-based tribofilm containing amorphous and graphite-like carbon nanoparticles. Since reliable carbon quantification by analytical TEM is difficult, RS is a useful complementary method for carbon identification at wear scars. KW - Raman spectroscopy KW - Cross-sectional TEM KW - Silicone oil residue KW - Tribofilm PY - 2015 DO - https://doi.org/10.1016/j.triboint.2015.04.046 SN - 0301-679X VL - 90 SP - 481 EP - 490 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-33421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Kloß, Heinz A1 - Österle, Werner T1 - Final outcome of a fundamental research project on tribofilms formed during automotive braking, Part 2: Numerical simulation T2 - EuroBrake 2014 (Proceedings) N2 - In part 1 it was shown that tribofilms usually are 100 nm thick and exhibit a multiphase nanocrystalline structure. The objective of our modelling efforts was to obtain a better understanding of the sliding behaviour and associated friction properties and to study the impact of internal and external parameters on these properties. The method of movable cellular automata (MCA) was used. The third bodies were considered as aggregates of linked nanoparticles which may decompose and form a layer of granulär material, the so-called mechanically mixed layer (MML), if certain fracture criteria are fulfilled. The basic model structure which consists of Fe3Ü4 nanoparticles with 13 % graphite inclusions was used. In order to assess the robustness of the model the following parameter studies were performed. The pressure ränge at an asperity contact was varied between 15 and 50 MPa. The mechanical properties of the oxide were varied between brittle and ductile behaviour corresponding to room temperature and high temperature behaviour. The mechanical properties of the soft ingredient were varied + 50 % of the properties of graphite. The influence T2 - EuroBrake 2014 CY - Lille, France DA - 13.05.2014 KW - Tribofilm KW - Third body KW - Dry friction KW - Modelling KW - Movable cellular automata PY - 2014 SN - 978-0-9572076-4-6 SP - 1 EP - 9 PB - FISITA CY - London AN - OPUS4-35040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. ED - Bartz, Wilfried J. ED - Friedrich Franek, T1 - Friction control during automotive braking - experimental observations and simulation at the nanometer scale T2 - 3rd Vienna International Conference - Nano-Technology T2 - 3rd Vienna International Conference - Nano-Technology CY - Vienna, Austria DA - 2009-03-18 KW - Bremse KW - Dritter Körper KW - Verschleiß KW - Reibung KW - Nanocharakterisierung KW - Modellierung PY - 2009 SN - 978-3-901657-32-0 SP - 335 EP - 341 AN - OPUS4-19222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. T1 - Friction control during automotive braking: experimental observations and simulation at nanometer scale JF - Tribology : materials, surfaces & interfaces KW - Friction control KW - Friction film KW - Automotive braking KW - MCA model KW - Nanostructure PY - 2009 DO - https://doi.org/10.1179/175158309X12586382418454 SN - 1751-5831 VL - 3 IS - 4 SP - 196 EP - 202 PB - Maney CY - London AN - OPUS4-20829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -