Effect of AlCoCrFeNi_2.1 Binder on Microstructure and Properties of WC-HEA Cemented Carbide

Aiming at the problem of high cost of Co binder in WC-Co cemented carbide tool materials, WC-HEA cemented carbides with 5%-20% of AlCoCrFeNi_2.1 high entropy alloy binder were prepared by spark plasma sintering (SPS). The microstructure, phase, hardness, fracture toughness and density were tested and analyzed. The feasibility of using AlCoCrFeNi_2.1 alloy powder instead of Co powder binder to manufacture WC cemented carbide was discussed. The results show that the microstructure of WC-HEA cemented carbide is composed of two phases of WC and HEA solid solution, and the average grain size of WC phase is 0.23-0.48 μm. With the increase of AlCoCrFeNi_2.1 binder content, the hardness of WC-HEA cemented carbide increases firstly then decreases, and the fracture toughness improves. The ultrafine-grained WC grains in WC-15% HEA less than 0.2 μm are the most, the average grain size of WC is only 0.23 μm, and the strength and toughness match is the best, the hardness is 1965 HV and the fracture toughness K_IC value is 13.6 MPa·m^1/2.