分子动力学模拟单晶纳米铝丝的拉伸破坏  

Molecular dynamics simulation of failure process of nano aluminum wire under axial tension

作　　者：黄丹[1] 陶伟明[1] 郭乙木[1] 

机构地区：[1]浙江大学力学系固体力学研究所,浙江杭州310027

出　　处：《兵器材料科学与工程》2005年第3期1-4,共4页Ordnance Material Science and Engineering

基　　金：国家自然科学青年基金项目(10302025)教育部留学回国启动基金(J20030151)

摘　　要：采用原子镶嵌势函数模拟单晶纳米铝丝在受单向拉伸时的变形破坏过程,分析了纳米铝丝的力学性能及微缺陷形成与演化过程。模拟表明纳米金属丝在无外载荷状态存在本征应力,原子缺陷从自由表面开始向内部扩展。自由表面发射位错,位错的移动消耗能量导致了纳米丝的塑性,自由表面原子的不稳定运动降低了纳米丝的强度。模拟得到单晶铝纳米丝的弹性模量和断裂强度,证明纳米丝的破坏从能量平衡角度符合Griffith断裂理论。With embedded atom method, a molecular dynamics simulation of the failure process of single crystal aluminum nano wire under axial tension was performed. The mechanical properties and the damage initiation and evolvement of monocrystalline aluminum was obtained. Simulation results show that free surfaces of nano wire lead to initial stress without external load, and damage expands from outmost surfaces deep into interior lattices. Ductility of nano metal stems from dislocation emited from free surfaces, and the instable motion of surface atoms decreases the strength of nano components. Atomistic simulation gets the Young' s modulus and fracture strength of nano aluminum wire and proves the accordance of failure on nano - scale with Griffith rupture theory.

关 键 词：分子动力学 镶嵌原子法 拉伸破坏 纳米铝丝 

分 类 号：O733[理学—晶体学] O561.1