Phase transformations in Titanium: Anisotropic deformation of ω phase

18th APS-SCCM; 24th AIRAPT

Zong, Hongxiang^1,2 ; Xue, Dezhen^1,2 ; Ding, Xiangdong^1,2 ; Lookman, Turab^2

State Key Laboratory for Mechanical Behavior of Materials, Xi'An Jiaotong University, Xi'an

710049, China^1

Theoretical Division, Los Alamos National Laboratory, Los Alamos

NM

87545, United States^2

关键词: Anisotropic deformation;    Mechanical behaviour;    Molecular dynamics simulations;    Non-uniform;    Omega phase;    Shear banding;    Uni-axial compression;    Uni-axial loading;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/11/112042/pdf
DOI  :  10.1088/1742-6596/500/11/112042

来源: IOP

【 摘 要 】

We study the plastic deformation of the ω phase which is obtained when Titanium undergoes a phase transformation under pressure. We perform molecular dynamics simulations under uniaxial loading and find that the ω phase not only shows brittle fracture upon loading in the [0001] direction, but also exhibits superplastic deformation features along the [100] direction. The brittle fracture is analogous to that which occurs in metallic glass by means of shear banding whereas the ductility is mediated by the α (hcp) to ω (hexagonal) phase transformation. We further show that the elastic deformation of the m phase is anisotropic; it can be non-uniform upon [0001] uniaxial compression. Our results provide insight into the mechanical behaviour of the m phase and imply that the transformation mediated ductility can lead to improvement of the plasticity of co-containing Titanium alloys.