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.