The recrystallization behavior of cryo- and cold-rolled AlCoCrFeNiTi high entropy alloy

The present work was conducted on the non-equiatomic Al_0·2Co_1·5CrFeNi_1·5Ti_0.3 high entropy alloy (HEA), which was separately subjected to 50% cold- and cryo-rolling. Subsequent annealing was performed within the temperature range of 800–1000 °C to investigate their recrystallization behavior. A partial recrystallization was achieved up to 900 °C for the cold-rolled material, while the cryo-rolled one had shown nearly fully recrystallized microstructure after 800 °C. A significant reduction in grain size from the solution-treated state (∼784 μm) to fully recrystallized state (∼71 μm for cold-rolled and ∼6 μm for cryo-rolled) was observed. A combined XRD and TEM analysis confirms that the cryo-rolled sample exhibits higher dislocation density than the cold-rolled sample, which resulted in faster recrystallization kinetics observed in the former than in the latter. Additionally, the Johnson–Mehl–Avrami–Kolmogorov model was employed to understand the recrystallization behavior.