A study of the lubricating mechanism of molybdenum disulfide

The structure of MoS2 and other layer lattice materials is discussed in relation to their effectiveness as lubricants and the mechanism of their lubricating actions. The mechanism of the lubricating action of MoS2 was studied and compared with that of other materials by scanning electron microscopical investigation of specimens tested in the LFW-1, Almen-Wieland and a deep drawing machine. The lubricating properties of MoS2 have been explained by the strong polarization of the sulfur atoms which produce a layer structure, good adhesion to metal surfaces, adhesion between MoS2 basal planes, easy sliding of MoS2 lamellae and the formation of a homogeneous continuous film. It is now shown that the load carrying part of the MoS2 film lies only on the asperities of the metal surface.