The evolution of microstructure of Ti–6Al–4V alloy during concurrent hot deformation and phase transformation

The microstructure development during concurrent hot deformation and β/α phase transformation in a Ti–6Al–4V alloy was investigated in detail. The influences of deformation during slow cooling on the stress–strain curve and microstructural morphology were established. The results showed that concurrent hot deformation and phase transformation can reduce α grain size and increase the kinetics of phase transformation remarkably. Such improvement in grain refinement and phase transformation is ascribed to the strain enhanced β/α phase transformation phenomena. Also, dynamic recrystallization and globularization of α layers were observed by deformation of sample to high strains, expecting considerable influence on mechanical properties.

► Concurrent hot deformation and phase transformation can reduce α grain size.
► Hot deformation increases the kinetics of phase transformation.
► Dynamic recrystallization and globularization of α layer are illustrated.
► We report a process called “strain enhanced phase transformation”.