液态金属原子自扩散的Enskog理论研究  

Enskog Theory of Self-Diffusion of Liquid Metal Atoms

作　　者：武秀秀 杨晓峰[1] WU Xiu-xiu;YANG Xiao-feng(School of Science,North University of China, Taiyuan 030051, China)

机构地区：[1]中北大学理学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2021年第3期213-217,共5页Journal of North University of China(Natural Science Edition)

摘　　要：为研究液态金属的自扩散行为,把液态金属看成硬球流体.考虑液态金属原子间碰撞深度随温度的升高而加大的问题,得到了硬球模型原子有效直径与温度的关系.进而对Enskog理论做出修正,得到能更准确地计算液态金属原子自扩散系数的公式.利用分子动力学软件LAMMPS模拟了液态金属铝、镁、铁的原子自扩散,得到了这些金属原子的自扩散系数,并与修正的Enskog理论计算结果进行了比较.结果表明:修正的Enskog理论更适用于硬度大的液态金属;温度比密度对液态金属原子的有效直径的影响小;密度的改变比有效直径的改变对液态金属原子的自扩散系数的贡献更大.Regarding liquid metal as the hard-spherical fluid was to study its self-diffusion behavior in this work.One problem was considered,which was the collision depth of liquid metal atom increases with the increases of temperature,and the relationship between effective diameter of atoms and temperature was discovered.Then,the Enskog hard sphere theory was revised,and a formula for calculating the self-diffusion coefficient of liquid metal atoms was obtained more accurately.We simulated the atomic self-diffusion of liquid metals aluminum,magnesium and iron base on the molecular dynamic software LAMMPS.The simulation results of their self-diffusion coefficients were compared with the modified Enskog theoretical calculations.The results show that the modified Enskog theory is more suitable for liquid metals with high hardness;the temperature has little effect on the effective diameter of liquid metal atoms than the density;the change in density of fluid contribute the major part to the self-diffusion coefficient of liquid metal atoms than the change in the effective diameter.

关 键 词：液态金属 Enskog理论 自扩散系数 分子动力学 

分 类 号：O469[理学—凝聚态物理]