Constitutive modeling of the hot deformation behavior of CoCrFeMnNi high-entropy alloy

The unfolding characteristics of high-entropy alloys (HEAs) are challenging traditional materials science field with promise for innovative applications, including aerospace and defence. This makes them strong candidates for future applications in the aerospace and defense industries. This research focuses on the hot compressive behavior of equiatomic CoCrFeMnNi alloy at strain rates of 0.01 s(-1) and 1 s(-1) and temperatures ranging between 200 and 800 degrees C. The experimental results were used to develop plastic flow stress models for a variety of existing constitutive models, namely, the Johnson-Cook, modified Johnson-Cook, Zerilli-Armstrong, modified Zerilli-Armstrong, Zener-Hollomon, Hensel-Spittel, and modified Hensel-Spittel. The models were then compared using the correlation coefficient (R) and average absolute relative error (AARE) to determine their suitability for predicting the deformation behavior of this alloy. The results show that the modified Johnson-Cook, Zener-Hollomon, Hensel-Spittel, and modified Hensel-Spittel models are all found to provide reasonable predictive accuracy for the studied alloy. Microstructural analysis was also conducted to compare the samples' microstructures before and after deformation to confirm the occurrence of discontinuous dynamic recrystallization when strained at 800 degrees C. This phenomenon explains the material's stress behavior at a lower strain rate, which affects the modeling results.