Optimization of the Hot Working Parameters and Constitutive Analysis of NiAlCrFeMo High-Entropy Alloy during Hot Forming

It is well known that high-entropy alloys (HEAs) possess excellent mechanical and physical properties, but their narrow hot working window makes it challenging to manufacture components through hot deformation. To optimize the hot processing window parameters, hot compression tests were conducted to construct a hot processing map, and a set of suitable constitutive equations was established to describe the hot deformation behavior of the NiAlCrFeMo HEA for numerical simulations. The hot compression experiments were performed using a Gleeble−3800 thermal simulator at deformation temperatures of 1373.15 K, 1423.15 K, and 1473.15 K, with strain rates of 0.001 s⁻¹, 0.01 s⁻¹, and 0.1 s⁻¹, respectively. The results of the processing map indicate that the optimal processing parameters are 1373.15–1423.15 K/0.001–0.01 s⁻¹, 1423.15 K/0.1–0.5 s⁻¹, and 1473.15 K/0.001 s⁻¹. The activation energy for dynamic recrystallization is 363.607 kJ/mol. The modified Arrhenius and Laasraoui-Jonas constitutive models were developed to predict the flow stress behavior, and the Laasraoui–Jonas model demonstrated good predictive capability.