Hot Working Parameters Optimization of TC4-DT Titanium Alloy Based on Processing Maps Considering True Strain

Elevated-temperature flow behavior of TC4-DT titanium alloy was investigated by isothermal hot compression tests at strain rate from 0.01 to 10 s−1 and temperature of 1181∼1341 K on Gleeble-3500 simulator. Three criterions including sensitive index of the strain rate (m-value), power dissipation factor (η-value) and flow instability (ζ-value) at different strains were analyzed by the principle of processing maps. As a result, the temperature at 1181∼1341 K and strain rate of 0.01∼0.79 s−1 is the optimum region in which dynamic recovery/dynamic recrystallization (DRV/DRX) occurs, and the corresponding power-dissipation efficiency is about 45%. The alloy exhibits flow instability regimes due to flow localization at higher strain rates(>1 s−1).