液态Ni-Al二元合金示踪扩散系数的分子动力学模拟  

Molecular Dynamics Simulations on Tracer Diffusivity in Ni-Al Binary Liquid Alloys

作　　者：王炜婷 王昊 鲁晓刚 WANG Weiting;WANG Hao;LU Xiaogang(Materials Genome Institute, Shanghai University, Shanghai 200444, China;School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China)

机构地区：[1]上海大学材料基因组工程研究院,上海200444 [2]上海大学材料科学与工程学院,上海200444

出　　处：《上海金属》2021年第3期108-111,共4页Shanghai Metals

基　　金：国家重点研发计划(No.2017YFB0701502)。

摘　　要：利用嵌入原子势(EAM)和修正嵌入原子势(MEAM)对液态Ni-Al二元合金的示踪扩散进行分子动力学(MD)模拟。首先计算了液态纯Ni和Al在不同温度下的自扩散系数,计算结果与试验数据吻合良好。然后对液态Ni-x%Al(x=1,2,5,10,原子分数)合金的示踪扩散系数进行MD模拟,得出热力学效应较物理尺寸效应对液相示踪扩散系数的影响更显著。并通过对分布函数分析得出,Ni-5%Al合金中Ni原子之间的间隙明显增大,导致该成分合金的示踪扩散系数最大。Molecular dynamics(MD)simulations of tracer diffusions of the liquid Ni-Al binary alloys were performed by using the embedded-atom method(EAM)and the modified embedded-atom method(MEAM).Firstly,the self-diffusion coefficients of liquid pure Ni and Al at different temperatures were calculated,which were in good agreements with the experimental data.Then MD simulations of tracer diffusivity in the liquid Ni-x%Al(x=1,2,5,10,atom fraction)alloys were carried out,it was found that the thermodynamic effect was more significant than the physical size effect on the tracer diffusivity.The pair distribution function analysis showed that the interstitial sites between Ni atoms in Ni-5%Al alloy increased obviously,which led to the maximum tracer diffusivity of the alloy.

关 键 词：示踪扩散 分子动力学 液态Ni-Al合金 

分 类 号：TG146.15[一般工业技术—材料科学与工程]