TY - CONF A1 - Wolter, Christian A1 - Österle, Werner A1 - Gradt, Thomas T1 - Metal sulphides as friction stabilisers under variable humidity N2 - Neben Kohlenstoff werden Metallsulfide in jeder Standardrezeptur für Bremsbeläge als Reibungsstabilisatoren verwendet. Um deren Wirkung zu untersuchen, wurden verschiedene Pulvermischungen in einer Stift-Scheibe-Anordnung tribologisch beansprucht, um künstliche dritte Körper zu erzeugen und zu testen, deren definierte Zusammensetzungen aus drei wichtigen Bestandteilen einer realen Reibschicht bestehen: Magnetit, Graphit und div. Metallsulfide. N2 - Besides carbon, metal sulphides are used in every standard brake pad formulation as friction stabilisers. In order to investigate their impact, various powder mixtures were tribologically stressed in a pin-on-disc device in order to produce and test artificial third bodies. containing the three main components of a real friction film, namely magnetite, graphite and a metal sulphide of interest. Since the sliding behaviour is influenced by the relative humidity the powder mixtures are tested at low, medium and high moisture levels. The tests revealed that the presence of graphite dominates the friction behaviour as well as the humidity sensitivity. The powders were prepared by either manual mixing or high energy ball-milling. Interestingly, all ball-milled blends provided coefficients of friction within the desired range for braking, which was attributed to the effect of zirconia particles from wear debris of the milling balls. The zirconia particles prevent the formation of solid lubricant films on the surfaces and support a homogeneous mixture of all constituents of the powder. Optimum brake performance is gained by an optimum combination of solid lubricants and abrasives. T2 - 57. Tribologie-Fachtagung CY - Göttingen, Germany DA - 26.09.2016 KW - Friction KW - Metal sulphides KW - Brake pad formulation PY - 2016 SN - 978-3-9817451-1-5 SP - 1.5/1 EP - 1.5/6 AN - OPUS4-37838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dmitriev, A. I. A1 - Österle, Werner T1 - Sliding simulation of automotive brake primary contact with variable amounts of copper and graphite nanoparticles 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). In the study the concentration of copper particles in a Fe3O4-matrix was varied. The sliding simulations were performed while assuming material properties at 500 degrees C in order to assess the beneficial role of copper during severe braking conditions corresponding to fading cycles during dynamometer testing. T2 - International Conference on Advanced Materials with Hierarchical Structure for New Technologies and Reliable Structures CY - Tomsk, Russia DA - 19.09.2016 KW - Polymer matrix composite KW - Silica nanoparticles KW - Friction KW - Wear PY - 2016 U6 - https://doi.org/10.1063/1.4966337 VL - 1783 SP - 020044-1 EP - 020044-4 AN - OPUS4-38933 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -