W-Y二元合金力学性质的第一性原理计算  

Mechanical Properties of W-Y Alloys by First-Principles Calculations

作　　者：姜迪友[1,2] 刘三秋[1] Jiang Diyou Liu SanqiuI(Nanchang University, Nanchang 330047, China Jiangxi University of Technology, Nanchang 330098, China)

机构地区：[1]南昌大学,江西南昌330047 [2]江西科技学院,江西南昌330098

出　　处：《稀有金属材料与工程》2016年第11期2895-2901,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金项目(11178002);国际合作项目(2015DFA61800);江西省创新团队项目(20133BCB2403);江西省科技创新项目(20114ACB00900)

摘　　要：采用基于密度泛函理论的第一性原理方法研究了钇的含量对W-Y二元合金力学性质的影响,精确计算了W_(1-x)Y_x(x=0.0625,0.125,0.25,0.5)合金的力学常数,并对其力学特性进行分析。结果表明,W-Y合金的弹性常数、体模量、杨氏模量以及剪切模量随Y含量(原子分数)的增加而成非单调性减小,表明Y对W材料的合金化降低了材料的机械强度。然而,基于力学特性B/G、泊松比ν和柯西压力C'等分析,Y的合金化对W的延展性和韧性有明显的提高。当Y含量x为0.25时,可有效改善W-Y合金的延展性和抗变形能力。通过态密度分析,W-Y合金的金属性随Y含量的增加先减弱而后增强。The effect of yttrium contents on the fundamental mechanical properties of W-Y alloys was studied by the first-principles method based on the density functional theory. The mechanical constants of W1-x Y x（x=0.0625, 0.125, 0.25, 0.5） alloys were calculated in solid solution model. According to the calculated mechanical constants, the mechanical properties were analyzed. Results show that the elastic constants, bulk modulus, Young’s modulus and shear modulus of W-Y alloys decrease non-monotonically with the increase of Y concentration, indicating that the doped Y decreases the mechanical strength of W materials. Based on the mechanical characteristics, such as B/G, Poisson’s ratio ν and Cauchy pressure C’, the ductility and toughness of the W-Y alloys are significantly improved with the increase of Y concentration. When the Y contents reaches 0.25, the ductility and the deformation resistance of W-Y alloys are largely enhanced. Through the analysis of the density of states, W-Y alloy metallic properties decrease and then increase as the concentration of Y increases.

关 键 词：第一壁材料 W-Y合金 力学性质 第一性原理 密度泛函理论 

分 类 号：TG146.411[一般工业技术—材料科学与工程]