Effect of Pre-cold Rolling-Induced Twins and Subsequent Precipitated ω-Phase on Mechanical Properties in a β-Type Ti-Mo Alloy

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2018,（6）
• 页码范围: 604-614
• 页数: 11页
• 语种: 英文

摘要

This paper reported an effectiveness of pre-cold rolling-induced {332} <113> twins combined with subsequent isothermal x-phase formation for enhancement of uniform elongation in a β-type Ti-15Mo alloy with high yield strength level. Mechanical {332} <113> twins were induced by cold rolling with an thickness reduction of 5％, which had little effect on x-phase precipitation after aging at 573 K for 3. 6 ks. Twinning after the cold rolling was further activated during tensile deformation, even with the presence of isothermal ω-phase. This combination of twins and x-phase enhanced uniform elongation from 0 to 9％ at yield strength level of 890 MPa. The high yield strength was mainly dominated by dislocation slip due to the isothermal ω-phase formation, and early onset of plastic instability after yielding was hindered due to the pre-cold rolling-induced twins. Dynamic microstructural refinement was induced by further twinning activation during deformation, which resulted in high work hardening rate corresponding enhancement of uniform elongation.