Strengthening mechanisms in high entropy alloys: A review

Abstract

High entropy alloys (HEAs) is a new generation of alloys with multi-component systems and emerged as a potential candidate for the industrial applications due to their excellent mechanical properties at cryogenic, ambient and elevated temperatures. The chemistry changes through microstructural heterogeneities leads to a significant strength increment in HEAs as compare to the conventional solid solutions. However, the strength increment is often related to the ductility loss and vice-versa, which is known as strength-ductility trade-off. Therefore, the modifications in the conventional strengthening mechanisms are required to overcome this dilemma. The conventional strengthening mechanisms have been revisited and revised by the materials scientists to break these trade-offs through adjusting the stacking fault energy, twins formation and phase transformation in multicomponent systems. Herein, the different strengthening mechanisms including, solid solution strengthening, grain boundary strengthening, precipitation strengthening and phase transformation strengthening are systematically reviewed with regard to overcome the strength-ductility trade-off in HEAs.