J. Mater. Sci. Technol. ›› 2023, Vol. 152: 30-36.DOI: 10.1016/j.jmst.2022.12.029

• Research article • Previous Articles     Next Articles

Stress-induced phase transformation and phase boundary sliding in Ti: An atomically resolved in-situ analysis

Zongde Koua, Xuteng Lia, Rong Huanga, Lixia Yangb,*, Yanqing Yangc, Tao Fenga,*, Si Lana,*, Gerhard Wildea,d, Qingquan Laie, Song Tanga,*   

  1. aHerbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
    bCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
    cState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
    dInstitute of Materials Physics, University of Muenster, Wilhelm-Klemm Street 10, Muenster 48149, Germany;
    eKey Laboratory for Light-weight Materials, Nanjing Tech University, Nanjing 210009, China
  • Received:2022-09-02 Revised:2022-11-14 Accepted:2022-12-09 Published:2023-07-20 Online:2023-02-11
  • Contact: *E-mail addresses: . lixiayang@nuaa.edu.cn (L. Yang), tao.feng@njust.edu.cn (T. Feng), lansi@njust.edu.cn (S. Lan), stang12s@alum.imr.ac.cn (S. Tang)

Abstract: In-situ tensile experiments on pure Ti were performed in a transmission electron microscope at room temperature. The dynamic process of stress-induced hexagonal closed-packed (hcp) to face-centered cubic (fcc) structural transformation ahead of a crack tip was captured at the atomic level. Intriguingly, a sliding behavior of the ensuing (0001)hcp/($1\bar{1}1$)fcc phase boundary was observed to further accommodate the plastic deformation until crack initiation. The sliding was accomplished via the successive conservative glide of extended dislocations along the (0001)hcp/($1\bar{1}1$)fcc phase boundary. A molecular dynamics simulation was carried out to corroborate the experiments and the results confirm the new dislocation-mediated sliding mechanism.

Key words: In situ HRTEM, Hcp-to-fcc transformation, Pure Ti, Phase boundary sliding, Molecular dynamics simulation