TY - JOUR A1 - Österle, Werner A1 - Dmitriev, A. I. A1 - Wetzel, B. A1 - Zhang, G. A1 - Häusler, Ines A1 - Jim, B.C. T1 - The role of carbon fibers and silica nanoparticles on friction and wear reduction of an advanced polymer matrix composite N2 - Excellent tribological properties of an advanced polymer matrix composite were obtained by a combination of micro- and nano-sized fillers. Surface features and the nanostructure of tribofilms were characterized by advanced microscopic techniques, and correlated with the macroscopic behavior in terms of wear rate and friction evolution. A model based on movable cellular automata was applied for obtaining a better understanding of the sliding behavior of the nanostructured tribofilms. The failure of the conventional composite without silica nanoparticles could be attributed to severe oxidational wear after degradation of an initially formed polymer transfer film. The hybrid composite preserves its antiwear and antifriction properties because flash temperatures at micron-sized carbon fibers, lead to polymer degradation and subsequent release of nanoparticles. It has been shown that the released particles are mixed with other wear products and form stable films at the disc surface thus preventing further severe oxidational wear. Furthermore, the released wear product also is embedding carbon fibers at the composite surface thus preventing fiber fragmentation and subsequent third body abrasion. With nanoscale modelling we were able to show that low friction and wear can be expected if the nanostructured silica films contain at least 10 vol.% of a soft ingredient. KW - Carbon fibers KW - Silica nanoparticles KW - Hybrid composite KW - Tribological properties KW - Tribofilm KW - Sliding simulation PY - 2016 U6 - https://doi.org/10.1016/j.matdes.2015.12.175 SN - 0264-1275 VL - 93 SP - 474 EP - 484 PB - Elsevier AN - OPUS4-35598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A.I. A1 - Österle, Werner A1 - Wetzel, B. A1 - Zhang, G. T1 - Mesoscale modeling of the mechanical and tribological behavior of a polymer matrix composite based on epoxy and 6 vol.% silica nanoparticles N2 - A model based on movable cellular automata (MCA) is described and applied for simulating the stress–strain and sliding behavior of a nanocomposite consisting of an epoxy matrix and 6 vol.% of homogeneously distributed silica nanoparticles. Tensile tests were used for verification of the model. It was realized that a slight modification of epoxy properties due to the addition of silica nanoparticles had to be taken into account in order to obtain good correlation between experimental and modeling results. On the other hand, sliding simulations revealed no susceptibility of results to slight modifications of matrix properties, but a significant impact of nanoparticles on the interface structure and smoothness of sliding mechanism. Furthermore, assuming both possibilities, bond breaking and rebinding of automata pairs, can explain different friction levels of polymer materials. KW - Nanocomposite KW - Stress–strain behavior KW - Movable cellular automata KW - Sliding simulation KW - Mechanically mixed layer KW - Coefficient of friction PY - 2015 U6 - https://doi.org/10.1016/j.commatsci.2015.08.029 SN - 0927-0256 VL - 110 SP - 204 EP - 214 PB - Elsevier CY - Amsterdam AN - OPUS4-34013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -