Plasma-electrolyte chemical-thermal treatment of hard alloy

The possibility of using of plasma-electrolytic treatment for the hard-alloy material surface complex modification, which consists of simultaneous diffusion saturation, heat treatment and plasma-electrochemical polishing of the surface, is shown. The phase composition, roughness and microhardness of the surface are studied, and tests for abrasive wear of nitrocarburized at different temperatures WC-Co8 hard-alloy plates are carried out. It is shown that plasma-electrolytic nitrocarburizing in an aqueous electrolyte based on carbamide and ammonium chloride leads to a change in the phase composition of the hard-alloy surface: strengthening oxide, nitride and carbide phases are formed. These changes lead increasing in the surface microhardness from 1800 to 2200 HV. As a result of anodic electrochemical dissolution, the roughness decreases by 2–4 times. The results of abrasive wear studies showed an increase in wear resistance by 25 % after nitrocarburization at a temperature of 850–950 °C. The results obtained confirm the potential of using plasma-electrolytic treatment processes for surface treatment of hard-alloy materials to improve operational characteristics. • Plasma-electrolytic treatment for WC-Co. • Saturation, heat treatment and polishing in one. • Microhardness and durability increasing, roughness reduction.