Optimization of forging process parameters of Ti600 alloy by using processing map

The hot deformation behavior of Ti600 titanium alloy has been studied using the processing map technique. Compression test with gleeble-1500 thermal simulator were performed in the temperature range of 800-1100°C and the strain rate range of 0.001-10s^-1. The flow stress data obtained from the test were used to develop processing map according to dynamic material model and Prasad's instability criterion. In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate. The map exhibits two domains of dynamic recrystallization occurring at the temperature range of 800-950°C in the strain rate of 0.003-1s^-1 and the temperature range of 970-1070°C in the strain rate range of 0.03-1s^-1, respectively. Moreover, the superplastic of Ti600 alloy occurs at low strain rate ranges of 0.001-0.01s^-1 and high temperature range of 930-1100°C with the peak efficiency higher than 60%, which are the optimum domain for hot working of Ti600 titanium alloy. The instability domain (flow localization and adiabatic shear) of flow behavior can also be recognized at the temperature range of 800-950°C in the strain rate of 0.03-10s^-1 and the temperature range of 1070-1100°C in the strain rate of 1-10s^-1. The evidences of deformation in these domains were identified and validated through microstructure observations.