First-Principles Calculations for Stable β-Ti-Mo Alloys Using Cluster-Plus-Glue-Atom Model

• 作者: Chang Pang Chuang Dong Fushi Jiang Jijun Zhao Qing Wang Zhaoyang Zheng
• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2020,（7）
• 页码范围: 968-974
• 页数: 7页
• 语种: 英文

摘要

Construction of suitable structural models in order to account for chemical short-range orders is the reason behind the difficult multi-scale computational simulation methods for solid solutions.Herein,using Ti-Mo alloys as representative,we used our cluster-plus-glue-atom model to address the chemical short-range orders for body-center cubic lattice.In accordance with the atomic interaction mode,an Mo solute atom would prefer 14 Ti solvent atoms as its nearest neighbors,forming a rhombic-dodecahedral cluster,and some next outer-shell Mo and Ti atoms would serve as the glue atoms,which is formulated as[Mo-Ti14](Mo,Ti)x.The number of glue atoms x corresponds to different spatial distribution of the clusters.One of the formula having good stability is[Mo-Ti14]Mo,i.e.,with one Mo as the glue atom.To verify its stability,mechanical properties and electronic density of state are obtained using the first-principles calculations and the Young's modulus agrees with the experimental values.Also the formulated structural unit[Mo-Ti14]Mo is indeed verified by the cluster expansion method.This work then confirms the existence of simple structural unit covering the nearest neighbors and a few next outershell atoms for the Ti-Mo alloy of high structural stability.