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

Area of Science:

• Materials Science
• Metallurgy
• Alloy Design

Background:

• Eutectic high-entropy alloys (EHEAs) offer a promising combination of hard and ductile phases for mechanical applications.
• Current EHEA performance often falls short of desired application requirements.

Purpose of the Study:

• To introduce a novel design strategy for EHEAs.
• To precisely regulate the composition of each phase in dual-phase alloys.
• To enhance overall strength and ductility through integrated strengthening mechanisms.

Main Methods:

• Precise composition regulation of individual phases within the dual-phase alloy.
• Introduction of a hierarchically heterogeneous microstructure.
• Integration of multiple strengthening mechanisms including phase transformation, twinning, and nanoprecipitates (NPs).

Main Results:

• Achieved an ultimate tensile strength of 1571 MPa and a uniform elongation of 22%.
• Reached a maximum strength of 2045 MPa.
• Maximized specific ultimate tensile strength to 273 MPa cm³ g⁻¹ due to high Al content reducing density.

Conclusions:

• The developed multi-mechanism assisted strengthening (MMAS) strategy effectively enhances both strength and ductility in EHEAs.
• This approach provides a viable pathway for designing advanced dual-phase alloys.
• The high specific strength makes these alloys attractive for weight-sensitive applications.