金属Cu体熔化与表面熔化行为的分子动力学模拟与分析  

MOLECULAR DYNAMICS SIMULATION AND ANALYSIS OF BULK AND SURFACE MELTING PROCESSES FOR METAL Cu

作　　者：王海龙[1] 王秀喜[1] 梁海弋[1] 

机构地区：[1]中国科学技术大学中国科学院材料力学行为和设计重点实验室,合肥230026

出　　处：《金属学报》2005年第6期568-572,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目10172081

摘　　要：采用Mishin嵌入原子势,通过分子动力学方法模拟了金属Cu原子体系的体熔化和表面熔化行为,分析了体熔化过程中系统结构组态和能量变化以及表面熔化过程中固-液界面迁移情况.模拟结果表明:在体熔化过程中,结构组态与能量在1585K处发生突变;在表面熔化过程中,固-液界面在1380K保持静止.两种熔化过程的不同发生机制是导致体熔点1585K高于热力学熔点1380K的原因.在实际熔化中,表面熔化处于支配地位,实验测量的是热力学熔点.得到的热力学熔点与实验结果吻合良好,验证了本文所采用方法是正确和有效的,同时也说明了Mishin嵌入原子势适合处理复杂无序体系.Molecular dynamics simulations of the bulk and surface melting processes were performed for metal Cu. The variations of the structure and energy in the system during bulk melting process were analyzed. The movement of the solid/liquid interface position during surface melting process was observed. The interaction between atoms in the system adopts the embedded atom potential proposed by Mishin. The simulation results show that the structure and energy in the system vary discontinuously at 1585 K in bulk melting process and the solid/liquid interface remains unchanged at 1380 K in the surface melting process. The different mechanisms of the two melting processes induce lower thermodynamic melting point (1380 K) than the bulk melting point (1585 K). Surface melting is significant in real melting process, so the experimental datum measured is the thermodynamic melting point. The simulated melting point coincides well with the experimental one, thus it can be concluded that the present melting point simulation method is correct and effective, and the Mishin's embedded atom potential is suitable for dealing with complicated and disordered systems.

关 键 词：CU 分子动力学 体熔点 热力学熔点 嵌入原子势 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TB115[金属学及工艺—金属材料]