Surface layer structure change and tribological property of Cu/FeS composite under electric field

The microstructural evolvement and friction performance of Cu/FeS self-lubricating composites within electric field were studied by molecular dynamics simulation. The atoms distribution and movement of the Cu/FeS composite under different electric field strengths were considered. The results show that some Fe atoms and S atoms break away from the original structure and move along the electric field, but the movement of Fe atoms and S atoms is not synchronized in stronger electric field strength. Thus, the whole material system becomes chaotic and its temperature rises. The unevenly electric field force appears in the material for the nonuniform FeS distribution, so the internal stress of the composite is generated. For the internal solid lubricating phases move along the direction of the electric field to the surface of the composite, the adhesive wear and the friction coefficient reduce. The movement of the phases leaves over some voids in the composite, which induces arc wear easily.