纳米多晶Ni微观结构与力学性能的分子动力学模拟  

Molecular dynamics simulation of microstructures and mechanical properties of nanocrystalline Ni

作　　者：肖时芳[1] 邓辉球[2] 陈曙光[2] 胡望宇[2] 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]湖南大学应用物理系,长沙410082

出　　处：《中国有色金属学报》2004年第7期1178-1182,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50371026);湖南省杰出青年基金资助项目

摘　　要：运用分子动力学技术,结合分析型嵌入原子方法(AEAM)模拟计算了平均晶粒尺寸为2.09～5.23nm的纳米多晶Ni的微观结构和力学性能。从原子能量分布、径向分布函数(RDF)、局域晶序结构的角度分析了纳米多晶Ni的晶界和晶粒结构,发现晶界部分所占的比例随晶粒尺寸的减小明显提高,结构与普通微晶的相似,纳米晶体的结合能较普通晶体的低。单向拉伸模拟结果表明:纳米多晶Ni的强度与晶粒尺寸之间出现反常Hall Petch关系;弹性模量的降低与纳米尺度结构特征相关。The nanostructures and mechanical properties of nanocrystalline Ni with average grain size ranging from 2.09 nm to 5.23 nm were simulated with analytic embedded-atom method(AEAM) and Molecular Dynamics(MD). The grain boundary(GB) and nanocrystalline grain structure were analyzed with radial distribution function(RDF), energy analysis and common neighbor analysis(CAN) methods. The results indicate that the fraction of GB increases with the grain size decreasing and the GB structure is similar to that of the conventional coarse crystalline. The binding energy of nanocrystalline is lower than that of conventional microcrystal. Stress—strain curves show the reverse Hall-Petch relation in the present simulations. The decrease of elastic modulus is dependent on the nanostructure.

关 键 词：纳米晶 嵌入原子方法 分子动力学 力学性能 

分 类 号：TG113.25[金属学及工艺—物理冶金]