Microstructure study of cold rolled Al0.32CoCrFeMnNi high-entropy alloy: Interactions between recrystallization and precipitation

The equimolar CoCrFeMnNi alloy is widely studied for its excellent mechanical properties at cryogenic temperatures. Interestingly, it presents a unique combination of strength and ductility mainly due to the occurrence twinning these low Motivated by desire improve room temperature strength, this study focuses on optimization microstructure through alloying thermomechanical treatments. More specifically, effect with aluminium aim triggering precipitation strengthening. composition Al0.32CoCrFeMnNi chosen basis thermodynamic data submitted various processing routes including cold rolling annealing steps. shown be key parameter determining governing transformations. At temperatures below 900 °C, main phenomenon taking place. Above recrystallization evolution microstructure. both mechanisms occur simultaneously. Recrystallization occurs first grain boundaries shear bands while activated in recrystallized unrecrystallized regions distinctive morphologies. It impede further recrystallization. Thermodynamic calculations are performed explain sequence observed regions. By increasing level from 60% 80%, kinetics accelerated complete reached. A wide range achieved variety treatments explored study. These microstructures turn translate into hardness levels tensile properties.