多级纳米孪晶金属在孪晶界处的堆积位错密度的本构模型和裂纹成核的准则  

Constitutive Model of Pile-Up Dislocations Density And Crack Nucleation Criteria at Twinboundary in Hierarchically Nanotwinned Metals

作　　者：王原琛 周剑秋[1,2] 王蒙晰 WANG Yuanchen;ZHOU Jianqiu;WANG Mengxi(Department of Mechanical and Dynamic Engineering,Nanjing Tech University,Nanjing 211800,China;Department of Mechanical Engineering,Wuhan Institute of Technology,Wuhan 430070,China)

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211800 [2]武汉工程大学机械工程学院,湖北武汉430073

出　　处：《热加工工艺》2021年第8期38-44,共7页Hot Working Technology

基　　金：国家自然科学基金(11272143,10872087,10502025);教育部科学技术研究重点项目(211061);江苏省普通高校研究生科研创新计划(CXZZ11_0342)。

摘　　要：通过特征体积单元假定孪晶界间距是服从对数分布,同时定量的去讨论在初级孪晶界与晶界交界处和初级孪晶界与次级孪晶界交界处的裂纹成核的机理。基于此研究方向,提出一个自相关性本构模型去定量的描述裂纹成核的准则。结果表明:位错堆积能会随着孪晶界厚度的增大而增大。而且,计算得到的位错堆积能与经验值存在着差异。By using representative volume element,the distribution of the twin lamellae spacing was supposed as a lognormal distribution.At the same time,the crack nucleation mechanis of the junction between primary twin boundary and grain boundary and the junction between primary twin boundary and secondary twin boundary was quantitatively discussed.Based on that,a relevant model was established to describe the crack nucleation criteria quantitatively.The results show that with the increase of the thickness of twin boundary,the energy of pile-up dislocations increases.Moreover,the difference between the energy of calculated pile-up dislocations and the experienced value is presented.

关 键 词：多级孪晶层 初级孪晶界间距分布 位错堆积能 裂纹成核 位错密度 

分 类 号：TG111.2[金属学及工艺—物理冶金] TG113.255[金属学及工艺—金属学]