Kinetics of growth of chalcogenide coatings on Mo, and the effect of the coating preparation conditions on their coefficients of friction

Synthesis of sulfide, selenide, and telluride coatings on Mo was investigated. The growth of the films in time is represented by a parabolic equation and is limited by diffusion through the chalcogenide film. Rate constants and activation energies of the processes were calculated. Tests of these coatings revealed that the low coefficient of friction of MoS/sub 2/ and MoSe/sub 2/ in vacuum and in helium is retained up to 600-800/sup 0/C, and in the case of MoTe/sub 2/ up to 400-600/sup 0/C. The optimum synthesis temperatures of lubricant coatings on Mo were established: 1000/sup 0/C for MoS/sub 2/, 800/sup 0/C for MoSe/sub 2/, and 750/sup 0/C for MoTe/sub 2/.