V-5Cr-5Ti合金弹性和力学性质的第一性原理研究

V-5Cr-5Ti合金作为核聚变堆第一包层的主要候选结构材料之一，但对其力学性质的理论研究相对较少.采用随机固溶体模型，利用第一性原理方法计算出V-5Cr-5Ti合金的弹性常数、体模量、剪切模量、杨氏模量、泊松比和柯西压力等，并与计算出的纯钒的相关数值进行对比，结果表明V-5Cr-5Ti合金具有良好的塑性和强度，但其塑性要略低于纯钒的.并对加入氧原子后的V-5Cr-5Ti合金进行了相关计算，通过对比计算结果发现，由于氧原子的加入，使V-5Cr-5Ti合金的塑性和强度都出现了不同程度的降低.最后对V-5Cr-5Ti合金和纯钒的理论强度进行了计算，并绘制出两者的应力-应变关系图，通过对比再次验证了上面的结论.

First-principles Study on Elastic and Mechanical Properties of V-5Cr-5Ti Alloy

V-5Cr-5Ti alloy is one of the main candidate structural materials for the first cladding of nuclear fusion reactor, but the theoretical research is relatively few on its mechanical properties. In this paper, the elastic constants, bulk modulus, shear modulus, Young''s modulus, Poisson''s ratio and Cauchy pressure of V-5Cr-5Ti alloy are calculated by using the random solid solution model and the first-principle method, and compared with the calculated correlation values of pure vanadium. The results show that V-5Cr-5Ti alloy has good plasticity and strength, but its plasticity is slightly lower than that of pure vanadium. The results show that the plasticity and strength of V-5Cr-5Ti alloy are reduced in varying degrees due to the addition of oxygen atom. Finally, the theoretical strength of V-5Cr-5Ti alloy and pure vanadium is calculated, and the stress-strain diagram of them is drawn. The above conclusion is verified again by comparison.