On the work hardening capacity of high entropy alloys during low-temperature deformation: A review

This comprehensive review provides detailed information on the work-hardening capability and unique deformation mechanisms of high-entropy alloys (HEAs) at low temperatures. The exceptional balance of strength and ductility in HEAs positions them as promising materials for extreme environments, including low-temperature applications. Temperature, strain rate, strain level, initial microstructure, composition, precipitation, phase transformation, dislocation substructure, stacking fault energy (SFE), and grain boundaries were identified as significant factors influencing deformation mechanisms in HEAs at low temperatures. The nucleation and propagation of deformation twins during low temperature plastic deformation significantly contribute to improving strength and ductility. Similarly, temperature-dependent strain-induced transformations greatly influence the work-hardening behavior of these materials. The formation of stacking faults (SFs) and their role in strain hardening were thoroughly examined due to their profound impact on dislocation mobility and overall strength. Furthermore, dislocation hardening, arising from dislocation pile-ups, interactions with obstacles, geometrically necessary dislocations (GNDs), and the formation of dislocation cells and walls, contributes to the impressive mechanical characteristics of HEAs at low temperatures. Understanding and controlling the intricate relationship between microstructure and mechanical properties are crucial for fully harnessing the potential of HEAs in low-temperature environments.