First-principles investigation on mechanical behaviors of W-Cr/Ti binary alloys

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• 作者：Yuming Ma ; Quan-Fu Han ; Zhen-Yu Zhou ; Yue-Lin Liu ; ^{liuyl@ytu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：W alloy ; Elastic properties ; Mechanical properties ; First-principles
• 刊名：Journal of Nuclear Materials
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：468
• 期：Complete
• 页码：105-112
• 全文大小：988 K

文摘

Using first-principles simulation, we have performed the study on the mechanical behaviors of body-centered-cubic W_1-xCr(Ti)_x binary alloys (0 < x < 0.1) as a function of Cr (Ti) composition. The lattice constants, elastic constants, Young's moduli, and shear moduli are investigated for single crystal W_1-xCr(Ti)_x binary alloys. Cr and Ti can, respectively, shrink and enlarge the lattice structure of W due to their different atomic radius. The influence of alloying on C₁₁ is larger than that on C₁₂ and C₄₄ with the increase of Cr/Ti concentration. For polycrystalline W-based alloys, bulk modulus B, Young's modulus E, shear modulus G, Poisson's ratio v, Zener anisotropy factor A, Debye temperature Θ_D, and B/G have been also calculated. All these quantities display regular change trend with increasing Cr/Ti concentration. Cr and Ti exhibit the opposite alloying effect on the thermodynamic stability of alloy. W_1-xCr(Ti)_x is energetically unstable (stable) with random Cr (Ti) concentration at any temperature considered in the current study. This result well approves the experiment on that the alloying element Ti can enhance the mechanical properties at ambient and intermediate temperatures.