循环加载条件下纳米晶铜的分子动力学模拟  

Molecular Dynamics Simulation of Porous Nanocrystalline Cu Void Under Cyclic Loading Condition

作　　者：杨宝童 周剑秋[1] 张峰 佟尚 YANG Baotong;ZHOU Jianqiu;ZHANG Feng;TONG Shang(School of Mechanical Engineering,Nanjing Tech University,Nanjing 210000,China)

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京210000

出　　处：《热加工工艺》2020年第6期33-36,共4页Hot Working Technology

基　　金：国家自然科学基金项目(10502025,10872087,11272143)。

摘　　要：使用分子动力学模拟(MD)来研究晶粒尺寸为5 nm的纳米晶Cu的疲劳行为。疲劳模拟是在±5%的应变幅度下进行5个周期的循环加载,分别模拟三种具有不同尺寸孔洞的样品。分子动力学模拟结果表明,循环加载下的变形行为主要是堆垛层错的部分位错滑移。随着孔洞尺寸的增加,材料变形的主要机制从整个模型的剪切变形演变到主要在孔洞边缘引起的局部应力集中。MD模拟结果表明,应力-应变行为的特征是初始软化,其次是硬化,这种现象也与空洞的尺寸有关。Molecular dynamics(MD)modeling was carried out to study the fatigue behavior of nanocrystalline Cu with the grain size of 5 nm.The fatigue simulation was performed by using cyclic loading at strain amplitude of ±5% for 5 cycles.The samples with three different size of voids were simulated.The results of MD simulation show that the deformation behavior under cyclic loading is mainly partial dislocation slip of the stacking faults.With the increase of void size,the principal mechanism of material deformation varies from shear deformation evolution throughout the model to the local stress concentration induced by the edge of the void.The results of MD simulation show that the stress-strain behavior is characterized by initial softening,followed by hardening,and the phenomenon is also related with the void size.

关 键 词：分子动力学模拟 纳晶铜 孔洞 疲劳 

分 类 号：TG111.2[金属学及工艺—物理冶金]