Ti1-xWxC（x=0～1.00）固溶体型碳化物弹性性质的第一性原理研究

The first-principles study on the elasticity of Ti1-xWxC（x = 0～1.00） solid-solution carbides

采用基于密度泛函理论的第一性原理计算了Ti1-xWxC（x=0,0.10,0.20,0.30,0.40,0.50,0.75,1.00）8种碳化物的晶格常数、弹性性质和电子态密度,计算结果与报道的实验数据相一致。分析发现Ti1-xWxC的晶胞参数随W含量增加呈线性减小;Ti0.60W0.40C具有最大剪切模量237.46 GPa,Ti0.50W0.50C具有最小G/B值0.59,其韧性最佳;分析电子态密度得知该系列化合物除WC外均有明显的pd轨道杂化作用,从而导致其力学性能发生变化。

The lattice constants,elastic properties and electronic densities of Ti1-xWxC（x= 0,0.10,0.20,0.30,0.40,0.50,0.75,1.00）were calculated using the first-principles method based on the density functional theory.Results show that the calculated results are consistent with the experimental data reported. It is found that the lattice constant of Ti1-xWxC decreases linearly with the increase of tungsten content. Ti0.60 W0.40 C has a maximum shear modulus of 237.46 GPa,while Ti0.50 W0.50 C has the lowest G/B value of 0.59,and its toughness is the best. The results of electron density analysis show that these compounds have obvious pd orbital hybridization effect except WC,which leads to the change of mechanical properties.