Deformation behavior and processing maps of Ni₃Al-based superalloy during isothermal hot compression

To study the hot deformation behavior of Ni₃Al-based alloy, hot compression tests were conducted in the temperature range of 1050–1250 °C with the strain rates from 0.01 to 10 s⁻¹. With the increase in deformation temperature and the decrease in strain rate, flow stress of the Ni₃Al-based alloy would be decreased. Based on the obtained constitutive equation, the calculated values of peak flow stress are in good agreement with the experimental ones, and the activation deformation energy is determined as 802.71 kJ/mol. Moreover, by dynamic material model (DMM), processing maps of the hot-deformed Ni₃Al-based alloys are established. It is indicated that the optimum processing parameters for the studied alloy correspond to deformation temperature of 1250 °C and strain rates from 0.01 to 0.1 s⁻¹. Specimens deformed under the optimum processing conditions exhibit fine and uniform grains, which is a typical dynamic recrystallization (DRX) microstructure. The DRX degree could be effectively enhanced with the increase of deformation temperature and the decrease of strain rate.