Hot Deformation Behavior of a Novel Near-β Titanium Alloy Ti-5.5Mo-6V-7Cr-4Al-2Sn-1Fe in (α plus β) Phase Region

The hot deformation behavior of a novel near-beta titanium alloy Ti-5.5Mo-6V-7Cr-4Al-2Sn-1Fe in (alpha + beta) phase region in the temperature of 605 similar to 755 degrees C and strain rate range of 10(-3)similar to 10(-1)/s(-1) was investigated on the Gleeble-3800 thermo-mechanical simulator. The results showed that the deformation parameters can have a significant influence on flow softening behavior and the microstructure evolution, as well as dynamic recrystallization is remarkable at temperature 755 degrees C and strain rate 10(-3)s(-1). The flow stress decreases with the increase of temperature and decrease of strain rate. With the rise of temperature and strain rate, the content of alpha phase gradually decreases. During the thermal deformation process, the alpha phase content decreases with the increase of the strain rate and the size of alpha phase decreases with increasing temperature. alpha(GB) is short rod or spherical. And alpha phase precipitated after short-term aging preferentially nucleated within the grains after aging treatment. Moreover, the thermal-mechanical process does not induce alpha phase generation compared to general heat treatment.