Wear-resistance of high entropy cutting-tool materials

Abstract

The work objective is to study the wear resistance of the experimental hard alloys (EHA) and complex alloyed high-speed steels (HSS) under cutting, as well as to establish the interconnection between their tribological characteristics and the entropy values (thermal EMF). The experimental studies on the EHA wear are carried out under the longitudinal turning, and HSS - under the friction conditions and drilling operations. Molybdenum, iron, titanium and copper mono carbide alloys are inserted into the cobalt bonds. It is shown that in this case, both entropy and wear-resistance increase (up to 2.5-3 times) as compared to the VK8 base alloy. At the same time the optimum machining spectrum extends. The functional relation between entropy and thermal EMF of the HSS is established, and it is shown that the minimum values of the thermal EMF correspond to the high entropy values. The HSS wear rate under friction is lower and the guaranteed life of drills is higher in steels with a high entropy value. The results obtained should be applied to the forming operations for the cutting-tool materials (CTM) of the maximum wear-resistance, and when developing new CTM.