摘要
提出了一种新的纳米结构材料即梯度纳米孪晶界结构,并利用分子动力学方法计算了梯度纳米孪晶Cu的单轴拉伸和压痕的变形过程,分析了纳米孪晶界分布对位错机制的影响.结果表明,梯度纳米孪晶界主导的塑性变形可分为2类,不全位错主导了较厚的孪晶片层的塑性变形,较细孪晶片层的塑性变形由全位错主导.此外,提高孪晶界密度可以有效改善材料的强度和硬度.
Strengthening by twin boundaries at nanoscale and gradient surface nanocrystallization are two important strengthening approaches recently drawing considerable attention in the field of metallic material re- search. In the present work, a novel nanostructure, i.e., gradient nanoscale twin boundaries, is proposed. To re- veal their unique deformation mechanism, uniaxial tension simulations of gradient nanotwinned copper are inves- tigated by molecular dynamics simulations. The results show that partial dislocations govern the deformation of relatively thicker twins while full dislocations control the deformation of relatively thinner twin layers. Nanoin- dentation processes of gradient nanotwinned copper are also performed, providing insights on the strengthening and hardening effects of nanoscale twin boundaries.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第2期226-230,共5页
Acta Metallurgica Sinica
基金
国家自然科学基金项目11172264和11222218
浙江省重点科技创新团队计划项目2009R50010资助~~
关键词
分子动力学
纳米孪晶界
位错
强度中图法
molecular dynamics, nanoscale twin boundary, dislocation, strength
