Expanding of conditions for use of solid lubricant coatings based on molybdenum diselenide due to their sulfur doping

Abstract

Comparative studies of the tribological properties of MoSex /Mo and MoSexSy /Mo coatings in an environment of humid air and nitrogen at an increased contact load have been carried out. The coatings were obtained by pulsed laser deposition from a MoSe2 target, which ensured the formation of a nanocomposite structure consisting of an amorphous matrix and Mo nanoparticles. To dope the coatings with sulfur atoms, the MoSe2 target was ablated in H2S gas of varying pressure. It has been established that optimization of the reactive gas pressure is required to improve the tribological properties of the MoSex /Mo coatings. When sulfur atoms are introduced up to a concentration of 7...14 at. %, a significant increase in the wear resistance of the coatings was observed both during tribological tests in air and in nitrogen. In this case, a notice able effect was achieved in reducing the coefficient of friction. As a result of alloying with sulfur, the friction coefficient in air decreased to 0.035, and in nitrogen to 0.015. The results of the study of wear tracks and wear debris by micro-Raman spectroscopy are presented, which made it possible to reveal the features of tribo-induced processes in the created coatings.