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.

硬质合金由于具有硬度高、耐磨、强度和韧性好等一系列优良性能而被广泛用作刀具材料。稀土元素的加入可以提高WC-Co硬质合金的高温抗裂性和抗变形性。本文基于第一性原理方法建立了WC-Co模型。计算四个位置掺杂稀土元素的结构的能量，确定最稳定的结构，然后进行模型优化。计算了掺杂前后WC-Co的弹性常数、电子性质和热力学性质。此外，通过比较杨氏模量和泊松比的参数，分析了两种材料的弹性性能。通过计算两种结构的焓、熵、自由能和比热容，探索了它们的热力学性质。结果表明，掺杂稀土元素的硬质合金材料的综合性能得到显着提高。