DEPENDENCE OF ANTIFRICTION PROPERTIES OF SELF-LUBRICATING COPPER-BASED COMPOSITE ON THE ELASTOPLASTIC CHARACTERISTICS OF TRIBOSYNTHESIS REGION

摘要

Microindentation is used to examine the elastoplastic deformation of a self-lubricating copper-based antifriction composite. Its performance and wear resistance in high vacuum and in open air are studied. It is shown that the friction skin synthesized during sliding in vacuum differs from the original material not only in the phase and chemical composition, but also in the structural state and mechanical characteristics: it has high hardness and is very susceptible to stress relaxation. The self-organization of the skin in the friction region leads to the self-lubrication effect and thus to low friction coefficient, high wear resistance, and good performance of the tribosystem in vacuum as a whole. It is established that the susceptibility of the friction skin synthesized in open air to stress relaxation is insignificant because of lead oxidation and thus its lubricating properties decrease as well. The wear resistance of the material decreases and the wear rate and friction coefficient increase in friction in open air.