The .cu / Fes Composite Friction And Wear Properties And Microstructure Evolution

Because of the excellent tribological property, copper matrix composites with solid self-lubricating materials are the important development direction of the friction material fields. The studies of the composite are important to save energy consumption, prolong service life of mechanicals, improve reliability. The 15wt%Cu/FeS composite was prepared by the in-situ synthesized method. Cu, FeS and few Fe2O3 were determined in that material by the X-Ray and energy spectrum analysis in this paper.The samples were experimental tested and the morphologies of wear traces were microanalysis in the paper. The results of experiments showed that, the load and the sliding speed were changed in a certain range, the main wear mechanisms were adhesive wear and abrasive wear of the 15wt%Cu/FeS composite. when the sliding speed, the slide distance and the hardness of the composite were a invariant, the load was increased, the friction coefficient and wear were increased too, but when the load, the slide distance and the hardness of the composite were a invariant, the sliding speed was increased, the friction coefficient and wear were decrease. There were three morphologies of wear traces in the copper matrix composites with solid self-lubricating materials:the adhesive wear region which was obtained by the friction of matrix copper and couple materials; the antifriction region which was obtained by the friction of self-lubricating materials(FeS) and couple materials; the abrasive wear region which was obtained by the friction of Fe2O3 and couple materials under dry friction condition.Based on the friction experiments, the conductivity, micro-morphology under dry friction condition of the 15wt%Cu/FeS composite were analysed by the molecular dynamics simulation. At the same time, the current-carrying friction performances and the structure evolution were predicted by the simulation in different electric field strengthes. The results of simulation showed that the conductivity of the particle dispersion composite was related to temperature, and the dispersion degree of reinforced phase would affect the conductivity. The results demonstrated that the 15wt% Cu/FeS composite had excellent conductive property, which was suitabled for pantograph slider material. According to the transmission electron microscopy(TEM), the atomical models of 15wt%Cu/FeS composite were built, the friction performances were studied by numerical simulation, the results showed that, the FeS layered structure was formed, and which was sliping along the close-packed plane (0001), the solid self-lubricating film would decrease the wear of the composite, protecte the copper matrix, and prolong service life of couple materials. The effection of the sliding speed for the Cu//Cu friction pair was analyzed, and the results showed that adhesive wear was divided into three stages:the initial stage, few atoms was realigned on the surface; the middle stage, the confusion areas were forming; the last stage was serious adhesive.The results of simulation prediction based on different microstructures in different electric field strengthes showed that the motion of the reinforced phase(FeS) affected by the different electric field strength. the centers of gravity of Fe ions and S ions were separated. The effects of the direction of electric fields on the composite were very great difference, in which the most influential was direction of electric field was along [010]. The elevatory temperature, which was from the electric fields, and the geometrical configuration of Cu and FeS also effected the tribological properties of 15wt%Cu/FeS composite under strong electric field.