单晶金属锆结构相变和熔化的分子动力学研究

摘要

应用分子动力学模拟了不同结构的单晶锆样品.采用Finnis-Sinclair作用势,通过分子动力学模拟方法Large-scale Atomic/Molecular Massively Parallel Simulator,对三种不同结构的单晶金属锆样品进行模拟计算,研究了锆在加温加压下的相变结构.研究结果显示,单晶金属锆在加压到0.2 GPa时会由hcp结构(α相)转变成特殊六角结构(ω相);对hcp结构单晶金属锆逐步加温发现,当温度升至1 161K时会由hcp结构(α相)转变成bcc结构(β相),再继续加温到1 569 K时,bcc结构的单晶金属锆样品开始熔化,得到的热力学熔点为1 569 K与实验值基本吻合.%The three different kinds of structures of the single crystal zirconium samples were investigated by means of Large-scale Atomic/Molecular Massively Parallel Simulator(lammps).The Finnis-Sinclair potential was used to simulate three structures(α,β,ω)of phase transition in single crystal zirconium.The re sults show that the hexagonal close-packed structure(alpha phase)can transform into a special hexagonal structure(omega phase)when phase transition pressure of the single crystal is 0.2 GPa;phase transition temperature of metal zirconium from the hexagonal close-packed structure(alpha phase)to body-centered cubic structure(beta phase)is 1 161 K.The sample began to melt when the temperature is about 1 569 K.The thermodynamic melting point obtained is 1 569 K,which is in agreement with the experimental values.