Brittle-to-ductile transition in Ti-Pt intermetallic compounds

Beikai Zhao; Qinghua Zhang; Xiaoqian Fu; Dongxu Qiao; Ling Zhang; Xiao Chen; Lin Gu; Yiping Lu; Qian Yu

doi:10.1016/j.scib.2021.06.021

Brittle-to-ductile transition in Ti-Pt intermetallic compounds

Sci Bull (Beijing). 2021 Nov 30;66(22):2281-2287. doi: 10.1016/j.scib.2021.06.021. Epub 2021 Jun 25.

Authors

Beikai Zhao¹, Qinghua Zhang², Xiaoqian Fu¹, Dongxu Qiao³, Ling Zhang⁴, Xiao Chen⁵, Lin Gu², Yiping Lu⁶, Qian Yu⁷

Affiliations

¹ Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
² Beijing National Laboratory for Condensed Matter Physics, Collaborative Innovation Center of Quantum Matter, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
³ Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China.
⁴ College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China.
⁵ Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
⁶ Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China. Electronic address: luyiping@dlut.edu.cn.
⁷ Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: yu_qian@zju.edu.cn.

PMID: 36654456
DOI: 10.1016/j.scib.2021.06.021

Abstract

Phase transformation changes numerous properties of materials. Ti-Pt alloys have received much interest because of high martensitic transformation temperature. However, the intrinsic brittleness of these intermetallic compounds with low crystal symmetry and complicated phase structure limit their applications, especially when composition deviates from stoichiometry ratio. By performing in situ heating high-resolution scanning transmission electron microscopy experiment and micro-mechanical testing on Ti-35 at% Pt that contained majorly Ti₃Pt and αTiPt phases, it was found that precipitating herringbone twinned αTiPt islands within Ti₃Pt could occur upon heating, significantly refining mixed-phase structure. The refinement of multi-intermetallic mixed-phase structure endowed brittle material with remarkable capacity for plastic deformation and strain hardening. The plastic deformation mechanisms include phase transformation upon yielding and dislocation slips during hardening, which rarely occurs in intermetallic compounds with low symmetry. The strong interaction between different deformation modes even caused nano-crystallization along slip bands. The results demonstrate that brittle-to-ductile transition in intermetallic compounds can be achieved by tuning mixed-phase structure through phase transformations.

Keywords: Brittle-to-ductile transition; Ductility; Intermetallic compounds; Phase transformation; Structure refinement.