A strategy to design eutectic high-entropy alloys based on binary eutectics

Abstract

• we employed a useful strategy to design EHEAs and quickly locating eutectic compositions in multicomponent HEAs based on binary eutectic compositions. • Nb 0.62 Fe 1.98 Co 1.22 Ni 1.00 exhibits a fully eutectic microstructure confirmed by both SEM and DSC results • Our findings provide a new strategy for a starting point for quickly pinpointing EHEAs. Although eutectic high entropy alloys (EHEAs) display homogeneously fine microstructure, outstanding castability and promising industrial application potential, how to search for the eutectic compositions in multicomponent high-entropy alloys (HEAs) remains to be challenging. Herein, the strategy which was proposed for pinpointing good glass formers in the field of bulk metallic glasses was utilized for quickly locating EHEA compositions in Nb-(Fe, Co, Ni), Zr-(Fe, Co, Ni) and Hf-(Fe, Co, Ni) HEA systems based on the constituent binary eutectics. As a demonstration, the eutectic compositions in the Nb-(Fe, Co, Ni), Zr-(Fe, Co, Ni) and Hf-(Fe, Co, Ni) HEA systems were quickly determined using this new approach. The newly designed EHEAs showed ultrafine eutectic microstructures, good castability and decent compressive mechanical properties. Current findings clearly demonstrated that this proposed approach is effective for searching for eutectic compositions in HEAs, which will expedite alloy design of EHEAs with strong solid solution strengthening effects.