NbMoTaWV_(x)难熔高熵合金的微观结构和力学性能的第一性原理研究

First-principle study of the microstructure and mechanical properties of NbMoTaWV_(x) refractory high-entropy alloy

采用虚拟晶体近似固溶体模型,通过第一性原理方法研究V元素含量的变化对NbMoTaWV_(x)难熔高熵合金的晶体结构和弹性性质的影响.结果表明,NbMoTaWV_(x)难熔高熵合金均为单相无序体心立方结构,V较小的原子半径和密度导致合金的晶格常数和密度减小.V的添加会降低合金抵抗弹性形变的能力,但合金的韧性和各向异性会增强.价电子浓度可能是影响合金结构和力学性能的重要因素,价电子浓度降低,其晶体结构稳定性和理论强度有所下降,但韧性和各向同性会增强.

The first-principle method was used to study the effect of V element content change in the crystal structure and elastic properties of NbMoTaWV_(x)refractory high-entropy alloy through the virtual crystal approximation solid solution model.The results showed that the NbMoTaWV_(x)refractory high-entropy alloys had a single-phase disordered body-centered cubic structure,and the smaller atomic radius and density of V led to a decrease in the lattice constant and density of the alloy.The addition of V would reduce the ability of the alloy to resist elastic deformation,but the toughness and anisotropy of the alloy would increase.Valence electron concentration may be an important factor affecting alloy structure and mechanical properties.As the valence electron concentration of the alloy decreased,the stability of the crystal structure and theoretical strength of the alloy decreased,but the toughness and isotropy would increase.