使用Tight-binding势函数,对液态Cu在等温凝固过程中的结构变化进行了分子动力学模拟(MD模拟)计算,得到体系在不同温度下的双体分布函数和配位数分布等静态结构信息,对等温凝固过程中FCC短程有序结构可能发生的变化以及由此导致的H-A键型变化进行了分析,并结合键对分析方法计算了不同弛豫时间下典型短程有序结构的分布.计算表明,在Cu凝固结晶相变过程中1551键应是先向1541键转化,初始三维结构的形成可能主要依赖于Cu原子在两个方向上的扩散和弛豫.
A series of molecular dynamics simulations for the structure transformation of liquid Cu during isothermal solidification were performed with the Tight-binding potential. Static structural information on the pair distribution functions and the coordination number distribution at different temperatures were obtained while an analysis was carried out on the possible change of short-range ordered structure of FCC crystal and its resultant types of atom pairs by means of the Honeycutt-Anderesen pair analysis technique. The results indicate that the 1551 bonds change into the 1541 bonds during solidification process and the formation of initial three-dimensional structure depends mainly on the diffusion and relaxation of Cu atoms in two directions.