Theoretical calculation and analysis of new rare earth cemented carbide based on first-principles

Cemented carbide is widely used as tool material since it has a series of excellent properties such as high hardness, wear resistance, good strength and toughness. The addition of rare earth elements can improve the high temperature crack resistance and deformation resistance of WC-Co cemented carbide. In this paper, a WC-Co model was established based on the first-principles method. The energy of the structure doped with rare earth elements in four positions is calculated to determine the most stable structure, and then carry out the model optimization. The elastic constants, electronic properties, and thermodynamic properties of WC-Co before and after doping were calculated. Furthermore, the elastic properties of the two materials was analyzed by comparing the parameters of Young's modulus and Poisson's ratio. Their thermodynamic properties were explored by calculating the enthalpy, entropy, free energy and specific heat capacity of the two structures. The results shows that the comprehensive performance of cemented carbide materials doped with rare earth elements is significantly improved.