Characterization of hot deformation behavior of Ti60 alloy by using processing map

The hot deformation behavior of Ti60 titanium alloy was investigated at the temperatures ranging from 960°C to 111°C and the strain rates ranging from 0. 001 s^-1 to 10 s^-1 using hot compression tests. Processing map for hot working was developed on the basis of the Dynamic Materials Model. Its stress-strain curves revealed greater flow softening in the α+β field than that in the β field. In α+β field, flow softening was caused by break-up and globularisation of lamellar α as well as deformation heating during deformation. While in the β field,flow softening was caused by dynamic recovery and recrystallization. The material exhibited superplasticity with a peak efficiency of 60% at 990°C and 0. 001 s^-1, which was the optimum parameters for α+β field working. There were two instability fields in the processing map:960-970°C at 0. 18-10 s^-1 and 1010-1110°C at 0. 75-10 s^-1. These fields should be avoided due to the formation of the adiabatic shear bands during the deformation of Ti60 alloy.