Materials Science and Engineering

Origin of high strength and good ductility of TiH2-based powder metallurgy titanium alloy with discontinuous lamellar structures

  • 张海瑞,牛红志,杨 超,相 楠,张德良,陈拂晓
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  • 1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
    2. Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology, Luoyang 471023, China;
    3. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
    4. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

Online published: 2025-11-04

Abstract

A unique discontinuous lamellar microstructure of titanium alloys consisting of lamellar colonies at prior β-Ti grain boundaries and internal interwoven α-laths is prepared by a TiH2-based powder metallurgy method. The α-variants get various crystallographic orientations and become discontinuous during vacuum annealing at 700 °C. Remarkably, nanoscale phase δ-TiH compound layers are generated between α-laths and β-strips, so that dislocations are piled up at the α/δ/β interfaces during tensile deformation. This leads to dislocation slips being confined to individual α-laths, with different áa? slips and particularly pyramidal ác+a? slips being activated. The efficiency of wavy slip is promoted and the work hardening rate is enhanced. Finally, the combined effect of dispersed micro-shear bands and lath distortions is considered contributive for alleviating the stress concentration at grain boundaries, resulting in a high-promising synergy of enhanced ultimate tensile strength of 1080 MPa and good elongation to fracture of 13.6%.

Cite this article

张海瑞,牛红志,杨 超,相 楠,张德良,陈拂晓 . Origin of high strength and good ductility of TiH2-based powder metallurgy titanium alloy with discontinuous lamellar structures[J]. Transactions of Nonferrous Metals Society of China, 2024 , 34(10) : 3342 -3356 . DOI: 10.1016/S1003-6326(25)66884-1

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