Wear reduction mechanism of graphite and MoS2 in epoxy composites

In order to overcome the shortcomings of present switch slide baseplates, a kind of epoxy composite was designed as lubricating coatings for switch slide baseplates. The wear tests of epoxy composite specimens paired with A36 steel specimens under air-lubricated condition were carried out on a ring–block wear tester typed M200. After the wear tests, the worn surfaces of steel specimens were examined by XPS and SEM. Furthermore, the wear reduction mechanism of graphite and MoS2 was discussed. The results showed that the graphite in epoxy composite can reduce the friction coefficient effectively, and increase the wear resistance of the epoxy composite greatly. MoS2 in epoxy composite is translated to MoO3 during the wear tests. Consequently, the friction coefficient of the pair cannot be decreased because MoO3 has not a layer structure. But MoS2 can effectively improve the wear resistance of the composite through restraining the epoxy transfer from the surface of composite to the surface of A36 steel.