Microstructure and Mechanical and Tribological Properties of WC-Co-Ce Cemented Carbide: First-Principles Calculations and Experiments

Abstract:

The WC/Co and WC/CoCe interface models were constructed, and the interfacial energy, elastic constants, and charge distribution characteristics were calculated using first-principles calculations. WC-10Co, WC-10Co-0.5Ce, and WC-10Co-1Ce cemented carbides were fabricated via liquid-phase sintering. Microstructural analysis, mechanical testing, and friction and wear testing were conducted to investigate the influence of the rare earth element Ce on the overall performance of the cemented carbide. The calculated results indicate that doping with Ce promotes the formation of strong covalent bonds between W and Ce atoms at the interface, which increases the interfacial bonding energy, reduces the interfacial energy, and improves structural stability. Based on the elastic constants and electronic properties, it is predicted that the hardness, toughness, and wear resistance of the cemented carbide are enhanced. Experimental findings demonstrate that the optimal performance is achieved when the Ce content is 0.5wt%. At this concentration, the Vickers hardness reaches 1484 HV₃₀, the fracture toughness is 10.55 MPa?m^1/2, and the wear rate is 1.067×10^–5 mm³?N^–1?m^–1.