Hot Deformation and Workability of a CrCoNi Medium Entropy Alloy

Hot compression behaviors of CrCoNi medium entropy alloy are were performed on the Gleeble-3800 thermal simulator in the strain rate range from 0.01 to 10 s(-1) and the temperature range from 800 to 1100 degrees C. According to the true stress-true strain curves, the true stress decreases with the decreasing of strain rate and the increasing of deformation temperature. The experimental parameters were fitted, and a modified model based on Arrhenius hyperbolic sine was established. Among them, material constants such as, n, A, and Q are functions of strain. Meanwhile, the processing map of CrCoNi medium entropy alloy under different strain conditions are established. Importantly, the optimal domain of apparent flow stability can be determined as the deformation temperature from 900 to 1100 degrees C and the strain rate from 0.01 to 10 s(-1). The results indicate that the stability domain of the CrCoN medium entropy alloy has a wider range, and the strain has little effect on its processing performance.

Automated summary

Hot compression behaviors of CrCoNi medium entropy alloy were studied, revealing an optimal domain of processing stability under specific deformation temperature and strain rate. Material constants are related to strain, while the stability domain of the CrCoNi medium entropy alloy is wider with little effect of strain on processing performance.