Non-equiatomic FeMnCrNiAl high-entropy alloys with heterogeneous structures for strength and ductility combination

The development of sound cost-effective alloys is always the pursuit of engineering application materials. A nonequiatomic FeMnCrNiAl high-entropy alloy (HEA) has been processed by cold rolling and annealing to prepare samples with a fully-recrystallized structure, and composite structures of recovered and recrystallized structures. The composite structure with a dual heterogeneous structure of both the matrix and precipitates can be designed to provide a synergistic combination of strength and ductility at ambient and cryogenic temperatures. For the heterogeneous structure, the rule of the mixture has been applied to calculate the flow stress, revealing an extra strengthening component from dislocation hardening, precipitation hardening, and back-stress hardening. A minor multi-component incoherent B2 phase is still innocuous to low-temperature toughness.

Automated summary

The research demonstrates that nonequiatomic high-entropy alloys with fully-recrystallized and composite structures can provide a synergistic combination of strength and ductility at ambient and cryogenic temperatures. Calculations of flow stress using the rule of the mixture reveal the impact of various strengthening mechanisms on alloy performance.