This article deals with the new method for producing solid lubricant coatings on hard alloy tools by thermo-hydrochemical treatment (THCT). The results of investigation of the tribotechnical properties of solid lubricant coatings obtained on hard alloy ВК6 grade (94 % WC + 6 % Co) using THCT method are presented. The composition of the medium and the temperature and the time parameters of THCT process were optimized by the friction coefficient of solid lubricant coatings. The diagrams of “parameters of process–property” were constructed using mathematical models. Processing by optimal THCT regime of ВК6 hard alloy in hydrosol medium based on TiO2 - MoO3 makes it possible under the condition of lubrication absence to decrease the friction coefficient of hard- alloy surface by 3,8–4,2 times as compared with untreated.