High Specific Strength Eutectic High-Entropy Alloy: Collaborative Effects of TRIP, TWIP, and Nanoprecipitation

Eutectic high-entropy alloys (EHEAs), characterized by their combination of hard and ductile phases, hold broad application prospects in terms of mechanical properties. However, the current performance of these alloys is not satisfactory. Herein, a new design approach is presented for EHEAs, focusing on precise composition regulation of each phase in the dual-phase alloy. Hierarchically heterogeneous microstructure and integrating various strengthening mechanisms is successfully introduced such as phase transformation, twinning, and nanoprecipitates (NPs) into each single system. Finally, the overall strength and ductility are effectively enhanced. Specifically, the ultimate tensile strength is 1571 MPa, the uniform elongation is 22%, and the maximum strength can reach 2045MPa. Notably, the high Al content in the EHEA effectively reduces its density, resulting in the maximum specific ultimate tensile strength of 273 MPa cm³ g^-1 in HEAs. The multi-mechanism assisted strengthening (MMAS) strategy is expected to provide guidance for the design of dual-phase alloys like EHEAs in the future.