A novel Fe-rich Co-free high entropy alloys with low cost and excellent comprehensive mechanical properties

In this paper, a novel strategy for designing high entropy alloys (HEAs) with low cost and high mechanical properties was proposed. Accordingly, a Fe-rich Co-free Fe2CrNiSi0.3Al0.2 HEA was designed and fabricated by arc-melting. The results show that this HEA is mainly composed of FCC dendrites, while BCC phase locates at the inter-dendrite regions. Moreover, this HEA exhibits outstanding comprehensive mechanical properties among dual-phase HEAs produced via various fabrication methods considering its product of strength and plasticity as well as raw material cost. It is interesting that, compared to its Al-free FCC counterpart, this HEA has significant enhancement in yield strength and ultimate tensile strength, while its plasticity is merely slightly reduced. Further investigation reveals that the heterostructure in this HEA plays an important role in this phenomenon. This work provides a novel insight into the development of high-performance HEAs with broad applications.