Effect of High Hydrostatic Pressure Treatment of WC–15Co Cemented Carbide on Its Wear Resistance

Abstract

The study examined for the first time the effects of high (400 MPa) hydrostatic pressure (HHP) treatment on the phase composition and wear resistance of WC–15 wt % Co cemented carbide, as well as on the performance of tools equipped with this material during the smoothing of steel. The results demonstrated that HHP treatment induced a martensitic fcc → hcp transformation in cobalt, which enhanced the alloy’s strength. The impact of HHP treatment on the wear resistance of WC–15 wt % Co cemented carbide tools was investigated during the smoothing process of structural carbon steel 45. The treatment increased the tool’s wear resistance by 31%, compared to tools equipped with untreated cemented carbide. This improvement resulted from changes in the wear mechanism. While the wear of tools with untreated cemented carbide involved the detachment of massive clusters of WC and Co grains, the wear of tools with HHP-treated carbide was characterized by the removal of individual WC grains. One contributing factor to the observed effects is the compressibility of cobalt, which is twice that of tungsten carbide.