TC4时效相变及扩散连接的分子动力学模拟  

Molecular Dynamics Simulation of TC4 Aging Phase Transition and Diffusion Bonding

作　　者：刘小刚[1] 张顺 李百洋 郭海丁[1] Liu Xiaogang, Zhang Shun, Li Baiyang, Guo Haiding(Jiangsu Province Key Laboratory of Aerospace Power Systems, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

机构地区：[1]南京航空航天大学江苏省航空动力系统重点实验室,江苏南京210016

出　　处：《稀有金属材料与工程》2018年第10期3045-3051,共7页Rare Metal Materials and Engineering

基　　金：中央高校基本科研业务费(NS2016022)

摘　　要：利用分子动力学方法模拟研究TC4时效相变及扩散连接过程。采用混合势分析了TC4三元合金时效相变过程的径向分布函数以及不同晶体结构相对含量的变化。同时研究了不同保温温度下扩散连接过程的原子浓度分布、扩散连接宽度以及扩散系数。结果表明:在时效相变过程中,TC4结构变化主要表现为亚稳?相析出?新相,状态稳定后,?相含量达到23%,与实验结果吻合较好;TC4扩散连接过程中,主要是界面附近的钛原子进行扩散,钒原子扩散能力次之,而参与扩散的铝原子相对较少;相同条件下,扩散连接宽度与保温温度呈现较好线性关系;钛原子扩散系数与保温温度的倒数呈指数关系,计算结果与实验相符。The aging phase transition and diffusion bonding of TC4 was studied by a molecular dynamics method. The radial distribution function of TC4 ternary alloy and the relative content of different crystal structures were analyzed. At the same time, the atomic concentration distribution, diffusion connection width and diffusion coefficient of diffusion bonding process at different thermal insulation temperatures were studied. The results show that the structural changes of TC4 in the aging phase transition are mainly manifested by the precipitation of new ？ phase from the metastable ？ phase, and the ？ phase content reaches 23% after the state stabilizes, which is in good agreement with the experimental results. In the process of TC4 diffusion bonding, the titanium atoms near the interface dominate the diffusion, and the vanadium atom diffusion is the secondary, while the aluminum atoms are relatively few. Under the same conditions, the diffusion connection width and the thermal insulation temperature are in a good linear relationship. The diffusion coefficient of titanium is exponentially related to the temperature of heat preservation, and the results are in accordance with the experiment.

关 键 词：分子动力学 TC4三元合金 径向分布函数 相变 扩散系数 

分 类 号：TG146.23[一般工业技术—材料科学与工程]