Effect of initial microstructure on grain refinement under hot compression in CrMnFeCoNi high-entropy alloy with Al addition

The microstructural changes and flow behavior under hot compression at a temperature of 1173 K were examined for a six-component (CoCrFeMnNi)(92)Al-8 high-entropy alloy. The homogenized alloy, which was a single-phase solid solution with a face-centered cubic (fcc) structure, possessed a deformation microstructure with shear bands after hot compression and exhibited steady-state flow over a wide strain range. In contrast, the thermomechanically processed alloy, which was composed of an unrecrystallized fcc matrix and second phases (bcc and sigma), comprised fully recrystallized matrix grains of 0.8 mu m diameter after hot compression and displayed gradual strain softening from the early stages of deformation. The results demonstrated that the dense dispersion of the second phases in the thermomechanically processed alloy was quite effective for attaining fine grains by dynamic recrystallization upon hot deformation.

Automated summary

The microstructural changes and flow behavior of a six-component high-entropy alloy were investigated under hot compression at 1173K. Results showed that the thermomechanically processed alloy with dense dispersion of second phases displayed steady-state flow and achieved finer grains compared to the homogenized alloy.