文献类型：期刊文献

英文题名：Investigation on plastic deformation mechanism of gradient nano-polycrystalline pure titanium by atomic simulation

作者：Lin, Tingyi Liu, Shuai Qu, Pengju Zhao, Xiaoying

第一作者：Lin, Tingyi

通信作者：Liu, S[1]

机构：[1]Guizhou Inst Technol, Engn Training Ctr, Guiyang 550003, Peoples R China;[2]Guizhou Univ, Coll Mat & Met, Guiyang 550025, Peoples R China;[3]South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Peoples R China;[4]South China Univ Technol, Sch Mat Sci & Engn, Wushan Rd, Guangzhou 510640, Peoples R China

第一机构：贵州理工学院

通信机构：corresponding author), South China Univ Technol, Sch Mat Sci & Engn, Wushan Rd, Guangzhou 510640, Peoples R China.

年份：2023

卷号：215

外文期刊名：VACUUM

收录：;EI(收录号：20232914400630);Scopus(收录号：2-s2.0-85164661971);WOS:【SCI-EXPANDED(收录号:WOS:001048129100001)】；

基金：This work was financially supported by National Natural Science Foundation of China (No. 52161019) , Guizhou Provincial Department of Education Youth Science and Technology Talent Growth Project (No. [2018] 243 and [2022] 274) .

语种：英文

外文关键词：Molecular dynamics simulation; Gradient structure; Microstructural evolution; Plastic deformation; Pure titanium

摘要：A gradient-structure nano-polycrystalline (GS) model and two pure nano-polycrystalline (PS1 and PS2) models with different grain sizes of pure titanium are studied deeply via molecular dynamics (MD) simulations. The plastic deformation mechanism of these three models is investigated in depth through analyzing atomistic details during loading process. In this research, the inverse Hall-Petch relationship is found in pure titanium since the tensile strength is positively correlated with average grain size. The transition from hexagonal close-packed (hcp) to face-centered cubic (fcc) structure is delayed by the gradient structure during loading, leading to the attenuated lattice distortion and thus preventing crack generation. The GS model allows plastic deformation through grain reorientation and grain boundary migration, which effectively improves the plasticity of pure titanium. The 1/3<1-100> type dislocation is proved to be dominant during tensile deformation and the gradient structure can provide dislocation networks interacted with grain boundaries, thus enhancing the tensile strength of the pure nano-polycrystalline titanium. In addition, a weaker temperature dependence on tensile stress is found in GS model compared with PS1 and PS2 models. This work opens a novel avenue for fabricating bulk GS materials with expected mechanical properties through microstructural design.