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 degrees C to 111 degrees 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 alpha+beta field than that in the beta field. In a+beta field, flow softening was caused by break-up and globularisation of lamellar a as well as deformation heating during deformation. While in the beta field, flow softening was caused by dynamic recovery and recrystallization. The material exhibited superplasticity with a peak efficiency of 60% at 990 degrees C and 0. 001 s(-1), which was the optimum parameters for alpha+beta field working. There were two instability fields in the processing map: 960-970 degrees C at 0. 18-10 s(-1) and 1010-1110 degrees 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.