中国物理B ›› 2020, Vol. 29 ›› Issue (4): 46201-046201.doi: 10.1088/1674-1056/ab7188

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation

Minrong An(安敏荣), Mengjia Su(宿梦嘉), Qiong Deng(邓琼), Haiyang Song(宋海洋), Chen Wang(王晨), Yu Shang(尚玉)   

  1. College of Materials Science and Engineering, Xi'an Shiyou University, Xi'an, China, Fundamental Science on Aircraft Structural Mechanics and Strength Laboratory, Northwestern Polytechnical University, Xi'an, China
  • 收稿日期:2019-12-11 修回日期:2020-01-22 出版日期:2020-04-05 发布日期:2020-04-05
  • 通讯作者: Qiong Deng, Haiyang Song E-mail:dengqiong24@nwpu.edu.cn;gsfshy@sohu.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11572259), the Natural Science Foundation of Shaanxi Province, China (Grant Nos. 2019JQ-827, 2018JM1013, and 2018JQ5108), and the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (Grant No. 19JK0672).

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation

Minrong An(安敏荣)1, Mengjia Su(宿梦嘉)2, Qiong Deng(邓琼)2, Haiyang Song(宋海洋)1, Chen Wang(王晨)1, Yu Shang(尚玉)1   

  1. College of Materials Science and Engineering, Xi'an Shiyou University, Xi'an, China, Fundamental Science on Aircraft Structural Mechanics and Strength Laboratory, Northwestern Polytechnical University, Xi'an, China
  • Received:2019-12-11 Revised:2020-01-22 Online:2020-04-05 Published:2020-04-05
  • Contact: Qiong Deng, Haiyang Song E-mail:dengqiong24@nwpu.edu.cn;gsfshy@sohu.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11572259), the Natural Science Foundation of Shaanxi Province, China (Grant Nos. 2019JQ-827, 2018JM1013, and 2018JQ5108), and the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (Grant No. 19JK0672).

摘要: Using molecular dynamics simulations, the plastic deformation behavior of nanocrytalline Ti has been investigated under tension and compression normal to the {0001}, {1010}, and {1210} planes. The results indicate that the plastic deformation strongly depends on crystal orientation and loading directions. Under tension normal to basal plane, the deformation mechanism is mainly the grain reorientation and the subsequent deformation twinning. Under compression, the transformation of hexagonal-close packed (HCP)-Ti to face-centered cubic (FCC)-Ti dominates the deformation. When loading is normal to the prismatic planes (both {1010} and {1210}), the deformation mechanism is primarily the phase transformation among HCP, body-centered cubic (BCC), and FCC structures, regardless of loading mode. The orientation relations (OR) of {0001}HCP||{111}FCC and <1210>HCP||<110>FCC, and {1010}HCP||{110}FCC and <0001>HCP||<010>FCC between the HCP and FCC phases have been observed in the present work. For the transformation of HCP→BCC→HCP, the OR is {0001}α1||{110}β||{1010}α2 (HCP phase before the critical strain is defined as α1-Ti, BCC phase is defined as β-Ti, and the HCP phase after the critical strain is defined as α2-Ti). Energy evolution during the various loading processes further shows the plastic anisotropy of nanocrystalline Ti is determined by the stacking order of the atoms. The results in the present work will promote the in-depth study of the plastic deformation mechanism of HCP materials.

关键词: molecular dynamics simulation, nanocrystalline Ti, anisotropic plasticity, deformation mechanism

Abstract: Using molecular dynamics simulations, the plastic deformation behavior of nanocrytalline Ti has been investigated under tension and compression normal to the {0001}, {1010}, and {1210} planes. The results indicate that the plastic deformation strongly depends on crystal orientation and loading directions. Under tension normal to basal plane, the deformation mechanism is mainly the grain reorientation and the subsequent deformation twinning. Under compression, the transformation of hexagonal-close packed (HCP)-Ti to face-centered cubic (FCC)-Ti dominates the deformation. When loading is normal to the prismatic planes (both {1010} and {1210}), the deformation mechanism is primarily the phase transformation among HCP, body-centered cubic (BCC), and FCC structures, regardless of loading mode. The orientation relations (OR) of {0001}HCP||{111}FCC and <1210>HCP||<110>FCC, and {1010}HCP||{110}FCC and <0001>HCP||<010>FCC between the HCP and FCC phases have been observed in the present work. For the transformation of HCP→BCC→HCP, the OR is {0001}α1||{110}β||{1010}α2 (HCP phase before the critical strain is defined as α1-Ti, BCC phase is defined as β-Ti, and the HCP phase after the critical strain is defined as α2-Ti). Energy evolution during the various loading processes further shows the plastic anisotropy of nanocrystalline Ti is determined by the stacking order of the atoms. The results in the present work will promote the in-depth study of the plastic deformation mechanism of HCP materials.

Key words: molecular dynamics simulation, nanocrystalline Ti, anisotropic plasticity, deformation mechanism

中图分类号:  (Mechanical properties of nanoscale systems)

  • 62.25.-g
61.46.-w (Structure of nanoscale materials) 64.70.Nd (Structural transitions in nanoscale materials) 02.70.Ns (Molecular dynamics and particle methods)