Precipitation growth of a-phase along the interface in CoCrFeMnNi high-entropy alloy

The equiatomic CoCrFeMnNi high-entropy alloy (HEA) has a face-centered cubic (FCC) single-phase structure with a good balance of yield strength and elongation due to the twinning-induced plasticity (TWIP). In order to increase the usability of FCC-structured HEA, it is necessary to develop its mechanical properties. The hard precipitation of the a-phase might be a promising strengthening mechanism. Furthermore, developing an advanced manufacturing process is necessary to apply the a-phase-containing HEAs. This study focused on a-phase formation during annealing after hot compression of a CoCrFeMnNi HEA. The a-phase was primarily observed near the high-angle grain boundaries and acted as the obstacle for the boundary migration, resulting in grain growth during annealing. In addition, the development of the a-phase according to the interface type was investigated. This microstructure increased the hardness of the alloy and may contribute to the further development of high-strength HEAs.

Automated summary

This study focused on the formation of the α-phase during annealing of a CoCrFeMnNi high-entropy alloy (HEA) after hot compression. The α-phase was primarily observed near the high-angle grain boundaries and hindered boundary migration, resulting in grain growth during annealing. This microstructure increased the hardness of the alloy and may contribute to the further development of high-strength HEAs.