W-Cu合金力学性能的第一性原理计算

First-principles calculation of mechanical properties of W-Cu alloy

采用基于密度泛函理论的第一性原理分析方法的CASTEP软件,计算了W-Cu_(x)(x=6.25,12.5,18.75,25,31.25,37.5,43.75,50)合金的晶格参数、体模量、剪切模量、杨氏模量等力学常数,还计算了焓变值、能带结构、电子态密度和电荷布局,研究Cu不同含量对W-Cu合金力学性能的影响.结果表明:Cu的添加会增加W基体触头材料的可塑性,韧性大小随着Cu含量的升高而增加,在掺杂比例为43.75%时达到最大值,韧性增加使得产生微裂纹的概率减小;另外还计算了W-Cu合金的态密度、能带结构和电荷布局,结果表明随着Cu含量的增加,共价性降低,金属性增强,便于加工成型.

The lattice parameters,bulk modulus,shear modulus,Young's modulus and other mechanical constants of W-Cu_(x)(x=6.25,12.5,18.75,25,31.25,37.5,43.75,50)alloy were calculated by CASTEP software based on the first principles analysis method of density functional theory.The enthalpy change,energy band structure,electronic density of states and charge distribution were also calculated to study the effect of Cu content on the mechanical properties of W-Cu alloy.The results show that:the addition of Cu can increase the plasticity of W-based contact materials,the toughness increases with the increase of Cu content,and reaches the maximum value when the doping ratio is 43.75%,the increase of toughness reduces the probability of microcracks;in addition,the density of states,energy band structure and charge distribution of W-Cu alloy are calculated,and the results show that with the increase of Cu content,the decrease of covalency and the decrease of Au content,the increase of Cu content and the increase of Cu content can reduce the probability of microcracks,resulting in easy processing.