Friction and Wear Characteristics of Molybdenum Dithiocarbamate and Molybdenum Dithiophosphate

Abstract

The friction and wear characteristics of molybdenum dithiocarbamate (MoDTC) and molybdenum dithiophosphate (MoDTP) were examined under a reciprocating sliding condition by adding them to a pure hydrocarbon. Both MoDTC and MoDTP reduced the friction and wear. MoDTC formed a surface film composed mainly of MoS2. MoDTP formed less molybdenum compounds in the rubbing surfaces, which were composed mainly of MoS2 and FePO4 at 120 degrees C, und MoS2, MoO3 and FePO4 at 200 degrees C. A surface film containing MoS2 was effective in reducing the friction. The coefficient of friction was decreased with increasing the concentration of MoS2 in the surface film. MoDTC had a higher ability to form MoS2 than MoDTP. Therefore, MoDTC was superior in reducing friction to MoDTP.