Hot-deformation behaviour and flow-stress prediction of the TC4 alloy considering strain

To study the hot-compressive deformation behaviour of the TC4 alloy, isothermal compression tests were conducted at temperatures ranging from 700 degrees C to 900 degrees C, at 100 degrees C intervals, and at strain rates ranging from 0.1 s(-1) to 10.0 s(-1). The experimental results showed that the flow stress of the TC4 alloy increases quickly with an increase in the strain, reaches a peak value, and then decreases to a steady value. The results clearly indicated that dynamic recovery and recrystallization occur during the hot-compression tests. The flow stress of the TC4 alloy increases with a decrease in the deformation temperature and an increase in the strain rate. On the basis of the experimental results, a revised constitutive model describing the relationship among the flow stress, strain rate, and forming temperature of the TC4 alloy at elevated temperature was established. The flow-stress values predicted by the constitutive model agreed well with the experimental results.