TY - JOUR A1 - Ă–sterle, Werner A1 - Dmitriev, Andrey T1 - Some considerations on the role of third bodies during automotive braking T2 - SAE International journal of passenger cars: mechanical systems N2 - Third bodies, also termed friction layers, tribofilms or secondary contact patches, are layers of more or less compacted wear debris between pads and rotor of a disc brake. Our approach of assessing the sliding behavior and friction properties induced by third bodies has been: i) structural characterization after AK-master test procedure, ii) sliding simulation of model structures similar to the observed ones but with simpler and well defined compositions, and iii) verification of simulation results by pin-on-disc tests with artificial third bodies showing the same microstructures and compositions as the model structures. The idea was to simulate structure formation during real braking conditions by high energy ball milling of appropriate powder blends. The final outcome of numerous parameter studies was that a third body containing 15 vol% soft ingredients and 0-20 vol % hard ingredients, both distributed homogeneously in a nanocrystalline iron oxide matrix, should be most desirable for braking. This general description of the optimum third body structure and several parameter studies performed by modelling enabled us to interpret a number of features of the AK-master test procedure, such as i) friction evolution during bedding, ii) the role of solid lubricants in respect to the initiation of smooth sliding behavior, and iii) friction evolution during a single braking event (in-stop behavior). PB - SAE International CY - Warrendale, Pa. KW - Tribofilm KW - Thrid body KW - Friction material KW - MCA-modelling KW - Automotive braking PY - 2014 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/31930 AN - OPUS4-31930 SN - 1946-3995 SN - 1946-4002 VL - 7 IS - 4 SP - 1287 EP - 1294 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany