Microwave sintering of WC-HEA cemented carbide: Sintering process, microstructure and mechanical properties

Abstract

Microwave sintering is an efficient and green material preparation technology. Ultrafine crystalline WC-CoCrFeNiCu cemented carbide were fabricated by microwave sintering using mechanically alloyed high-entropy alloy (HEA) as a binder. The effects of the microwave sintering process (sintering temperature, holding time) on grain distribution, microstructure and mechanical properties of WC-HEA cemented carbide were studied. WC-10wt%HEA showed the best mechanical properties as sintered at 1400 °C with holding time of 10 min. Its grain size, Vickers hardness and fracture toughness were 273 ± 6 nm, 17.6 ± 0.8 GPa, and 8.7 ± 0.3 MPa·m1/2, respectively. The delayed diffusion effect of HEA played significant role in inhibiting grain growth, resulting in 38% smaller than that of WC-Co cemented carbide. Improving the wettability of HEA on WC to reduce the porosity of the sintered body is the main challenge in producing cemented carbide tool materials with HEA as a binder.