Multiple deformation mechanisms induce high work hardening in Ti–5Al–7.5 V alloy via transformed β matrix

In this work, different transformed β matrix was obtained in Ti–5Al–7.5 V alloy. The alloy with equiaxed α_p phase and transformed β matrix containing α′ martensite and β phase exhibits good combination of strength and plasticity, as well as a high work hardening rate. A concurrent operation of stress-induced α″ martensitic transformation, deformation twinning and dislocation slips was observed governing the deformation process of this alloy. The alloy with equiaxed α_p phase and transformed β matrix containing secondary α_s plates and retained β phase shows a high strength and plasticity but low work hardening rate, which is caused by dislocation slips. Highlights The quenched Ti–5Al–7.5 V alloy exhibits a high work hardening rate, approximately 5500 MPa. The dependence of work hardening rate of Ti–5Al–7.5 V alloy on transformed β matrix is revealed. Concurrent operations of stress-induced α″ martensitic transformation, deformation twinning and dislocation slips govern deformation of the studied alloy.