Sliding contact characteristics between self-lubricating composite materials and copper

Previous investigations of a composite material (CM-1) containing 20% of MoS/sub 2/ and 20% of WS/sub 2/ showed that whereas the coefficient of friction was reduced to that between pure copper metals by the incorporation of solid lubricants, contact resistance was increased by 1-2 orders of magnitude due to the presence of copper oxide film. Coefficients of friction and contact resistivities of two types of composite materials CM-4 (WS/sub 2/ 8%) and CM-5 (WS/sub 2/ 45%), with low resistivities were measured simultaneously using an experimental tester. It was found that the contact resistances were reduced to as low as 1/10 that of CM-1. Although coefficients of friction of 0.4-0.5, which were slightly higher than that of CM-1