Effect of Cold Isostatic Pressing on the Mechanical Properties of WC-8Co Cemented Carbide for Friction Stir Welding Tool

WC-8Co cemented carbide specimens were prepared via vacuum sintering. The effects of cold isostatic pressing (CIP) on microstructure and mechanical properties were investigated. The results show that only WC and Co3W3C (γ-phase) were detected by XRD without any else phases, even though Co. Dense WC-8Co cemented carbide samples were obtained and relative density reached over 98%. The pressing method, instead of pressure, took an important role in the mechanical properties of WC-8Co cemented carbide. KIC and TRS of WC-8Co cemented carbide were improved at least 27% and 24%, respectively, by the use of CIP. WC-8Co cemented carbide with excellent mechanical properties (HRA>93.5, KIC>11MPa·m1/2, TRS>870MPa) was obtained by using CIP.