55%Al-Zn合金熔体结构的从头算研究

Ab Initio Study on Melt Structure of 55% Al-Zn Alloy

采用第一性原理分子动力学模拟对高温55%Al-Zn合金熔体进行研究,给出熔体的结构和动力学性质。结果表明:计算得到的Al-Zn合金熔体的结构因子与实验结果符合较好。在加入Zn原子后,熔体中Al原子的分布变化不大,而Zn原子是随机均匀分布的;熔体中Al-Al配位数与Al-Zn配位数之比约为3:1,与熔体中原子含量的比值基本一致。同时研究表明,Al原子周围的第一近邻原子形成的笼体对Al原子运动的阻碍作用较强。

The first-principle molecular dynamics simulation was employed to study the melt structure of 55% A1-Zn alloy using Vienna ab initio simulation package （VASP）. The structure and dynamic properties of the melt were obtained. The results indicate that the calculation value of structure factor is in agreement with the experimental value. The atomic distribution of A1 does not apparently change after adding Zn atom. The ratio between the coordination number of A1-A1 and A1-Zn in A1-Zn alloy melt is about 3 ： 1 ,which is coincident with the ratio of the atom content in alloy melt. The Zn atom distributes randomly and homogeneously. The effects of cage A1 forms from nearest-neighbor atom on impeding motion were intensive.