Novel deformation twinning system in a cold rolled high-strength metastable-β Ti-5Al-5V-5Mo-3Cr-0.5Fe alloy

• Published in: Materialia Vol. 9; p. 100614
• Main Authors: Antonov, Stoichko, Kloenne, Zachary, Gao, Yipeng, Wang, Dong, Feng, Qiang, Wang, Yunzhi, Fraser, Hamish L., Zheng, Yufeng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2020
• Subjects: Deformation twinning; Stress-induced α″ martensite; Titanium alloys; {10 9 3} β; ω phase; ω phase; Titanium alloys; Deformation twinning; {10 9 3} β; Stress-induced α″ martensite
• ISSN: 2589-1529; 2589-1529
• DOI: 10.1016/j.mtla.2020.100614

A high-strength metastable β-titanium alloy, Ti-5Al-5Mo-5V-3Cr-0.5Fe (wt.%) was cold rolled at room temperature and characterized using scanning and transmission electron microscopy. A novel {10 9 3} β type deformation twining mode (Σ19a) is reported for the first time, and crystallographic analysis was carried-out to elucidate the origin of such high-index deformation twins. The initially β-solutionized alloy contains nano-scale ω phase, which is also subsequently distributed within the twins. Additionally, a thin nano-scale ω layer forms along the twin boundaries, and two variants of α″ martensite phase form inside the deformation twins. The current work opens up new prospects for improving the ductility of high-strength Ti alloys by inducing the twinning and transformation induced plasticity effects. [Display omitted]