Effect of different sintering temperatures on microstructure and mechanical properties of WC-10CuFeNiCrCo hard alloy

CuFeNiCrCo high-entropy alloy powder, as a binder, was sintered for 10 hours by high-energy ball milling with WC powder. Then, WC-10%CuFeNiCrCo hard alloys were prepared by discharge plasma sintering. The effects of different sintering temperatures (1 350℃, 1 420 ℃, and 1 480 ℃) on the microstructure and mechanical properties of WC-10CuFeNiCrCo hard alloys were studied. The results indicate that the solid-phase rapid densification time of HEA bonding phase alloys is earlier than that of Co bonding phase alloys, and no macroscopic pores, carbon-deficient phases, or free carbon are observed in WC-10CuFeNiCrCo hard alloys prepared at different sintering temperatures. With the increase of sintering temperature, the grain size of WC-10CuFeNiCrCo hard alloy increases first and then decreases. The lath-like coarse WC grains appear in the sintered alloy at 1 480 ℃, which reduces the peak strength of WC (0001) and shifts to a low angle. At a sintering temperature of 1350 ℃, the comprehensive performance of WC-10CuFeNiCrCo hard alloy is superior to that of WC-10Co alloy. The presence of coarse WC grains causes crack deflection and bridging during the crack propagation process, effectively hindering the diffusion and propagation of cracks.