Hot Deformation Behavior and Microstructure Evolution of Annealed CrFeCoNiAl0.1 High Entropy Alloy

The hot compression test of CrFeCoNiAl0.1 high entropy alloy at temperature range of 950-1100 & DEG;C and strain rates range of 0.001-1 s(-1) was carried out by Gleeble-3500 thermal compression simulator. The characteristics of microstructure evolution of the studied alloy during hot deformation were studied by means of OM and EBSD. The Arrhenius-type constitutive equation was constructed, and the hot deformation activation energy was calculated to be 307.77 K J mol(-1). The proportion of low angle grain boundaries is 10.2% at the condition of 1050 & DEG;C/0.01 s(-1), and the complete dynamic recrystallization (DRX) occurs. The characteristic parameters are determined according to the relationship between the work hardening rate and the true stress, and the mathematical relationship between the critical conditions for DRX and Z parameters is obtained. The critical stress for DRX decreases with increasing temperatures and decreasing strain rates. The kinetic model of DRX is constructed by the Avrami equation. Higher temperature and lower strain rate were beneficial to the occurrence of DRX. Based on microstructure evolution, the DRX volume fraction model of CrFeCoNiAl0.1 high entropy alloy was verified, and the experimental results are close to the predicted results. The DRX volume fraction model can correctly predict the DRX behavior of CrFeCoNiAl0.1 high entropy alloy.