TY - JOUR A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Gradt, Thomas A1 - Orts Gil, Guillermo A1 - Schneider, Thomas A1 - Dmitriev, A.I. T1 - Tribological screening tests for the selection of raw materials for automotive brake pad formulations N2 - A modified pin-on-disc test was applied to determine tribological properties of typical brake pad constituents. Ball-milling of these ingredients together with iron oxide and graphite provided model materials displaying the main features of real third bodies. Solid lubricants like graphite affected the friction and wear behaviour of Fe3O4 powders considerably whereas further addition of hard nanoparticles induced only minor effects. This was corroborated by comparison with modelling results. MoS2 played a dual role. Depending on special conditions, this ingredient either reduced or increased friction. The latter could be explained, after nanoscopic characterization, by oxidation and destruction of the wear-protecting tribofilm. KW - Brake pad formulation KW - Raw materials KW - Third body KW - Pin-on-disc test PY - 2014 U6 - https://doi.org/10.1016/j.triboint.2014.01.017 SN - 0301-679X VL - 73 SP - 148 EP - 155 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-30221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Österle, Werner A1 - Kloß, Heinz T1 - Nano-scale modeling of pad-disc interface. The influence of copper as a pad ingredient. T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Friction layer KW - Copper particles KW - MCA-modelling PY - 2010 SP - 1 EP - 6(?) AN - OPUS4-22656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Österle, Werner A1 - Kloß, Heinz A1 - Dmitriev, A.I. T1 - Modeling of Friction Evolution and Assessment of Impacts on Vibration Excitation at the Pad-Disc Interface T2 - 26th Annual Brake Colloquium & Exhibition CY - San Antonio, Texas, USA DA - 2008-10-12 KW - Friction materials KW - MCA-modeling KW - Friction films KW - Noise propensity KW - Friction-induced vibrations PY - 2008 SN - 978-0-7680-2097-7 IS - 2008-01-2582 SP - 303 EP - 311 AN - OPUS4-18695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A.I. A1 - Österle, Werner A1 - Kloß, Heinz T1 - Numerical Simulation of Mechanically Mixed Layer Formation at Local Contacts of an Automotive Brake System KW - Nanotribology KW - Automotive Brakes KW - Dynamic Modelling KW - Friction Mechanisms KW - Mechanically Mixed Layer KW - Movable Cellular Automata PY - 2008 U6 - https://doi.org/10.1080/10.40.2000802380314 SN - 1040-2004 SN - 1547-397X VL - 51 SP - 1 EP - 7 PB - Taylor & Francis CY - Philadelphia, Pa. AN - OPUS4-18696 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 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 U6 - 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 - 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) 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 - 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 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 - CONF A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Kloß, Heinz ED - Jayashree Bijwe, T1 - Basic considerations for the development of friction materials 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 - JOUR A1 - Österle, Werner A1 - Nikonov, A. Y. A1 - Dmitriev, A. I. ED - Krzanowski, J. T1 - MD sliding simulations of amorphous tribofilms consisting of either SiO2 or carbon N2 - The sliding behaviors of two simplified tribofilms with amorphous structure consisting either of SiO₂ molecules or C atoms were simulated by molecular dynamics modeling. The objective was to identify mechanisms explaining the experimentally observed lubricating properties of the two amorphous films. The impacts of layer thickness, normal pressure, temperature and different substrate materials were studied systematically, while the sliding velocity was kept constant at 30 m/s. While the layer thickness was not critical, all the other parameters showed special effects under certain conditions. Normal pressure impeded void formation and could even eliminate voids if applied at high temperature. Stick-slip sliding was changed to smooth sliding at high temperature due to void healing. Considering the carbon film, high friction forces and shearing of the entire film was observed with diamond substrates, whereas interface sliding at low friction forces and an amorphous layer of iron mixed with carbon was observed if the supporting substrates consisted of α-Fe. Both films show a decrease of friction forces and smooth sliding behavior at elevated temperature, corresponding well to the tribological behavior of and advanced nanocomposite sliding against a steel disc under severe stressing conditions when high flash temperatures can be expected. KW - dry friction KW - amorphous silica film KW - amorphous carbon film KW - sliding simulation KW - molecular dynamics PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-379367 VL - 4 IS - 24 PB - MDPI CY - Basel, Switzerland AN - OPUS4-37936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A.I. A1 - Österle, Werner T1 - Sliding simulations with variable amounts of copper and graphite mixed with magnetite N2 - Copper is one of the most important components in brake pads and its amount can reach up to 14%. In spite of a number of positive features copper usage in brake pad formulations has recently become the subject of considerable discussions, primarily due to concerns about potential risks related to environmental impacts of copper particles. So, for developing new pad formulations with possible replacements of copper content, it is very important to understand the functionality of copper additions to brake friction materials. In the paper theoretical investigation of the role of copper as a pad ingredient was carried out on the basis of modelling by the method of movable cellular automata (MCA). Our previous studies show that copper as a constituent of the tribofilm formed during braking provides smooth sliding by forming a granular layer of mechanically mixed materials from the friction layers. In the present study the concentration of copper particles in a Fe3O4-matrix was varied systematically in the range 5.5-28 vol. % and compared to mixtures with the same amount of graphite nanoparticles. The sliding simulations were performed while assuming material properties at 500°C in order to assess the beneficial role of copper during severe braking conditions corresponding to fading cycles during dynamometer testing. T2 - EuroBrake 2016 CY - Milano, Italy DA - 13.06.2016 KW - Movable cellular automata KW - Copper KW - Sliding simulation KW - Third body KW - Tribofilm PY - 2016 UR - www.eurobrake.net VL - EB2016-SVM-054 SP - 1 EP - 7 PB - FISITA AN - OPUS4-37938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -