Integrated Design of Aluminum-Containing High-entropy Refractory B2 Alloys with Synergy of High Strength and Ductility

TL;DR

This study combines machine learning and simulations to design aluminum-containing refractory high-entropy alloys with a focus on achieving high strength and ductility, providing a strategic framework for advanced alloy development.

Contribution

It introduces an integrated high-throughput approach using machine learning and Monte Carlo simulations for designing high-performance RHEAs with controlled phases and properties.

Findings

Achieved high compressive strength up to 1.6 GPa and fracture strains over 50%.

Identified a valence-electron-count domain linked to alloy brittleness.

Provided insights into element effects on atomic ordering and mechanical behavior.

Abstract

Refractory high-entropy alloys, RHEAs, are promising high-temperature structural materials. Their large compositional space poses great design challenges for phase control and high strength-ductility synergy. The present research pioneers using integrated high-throughput machine learning with Monte Carlo simulations to effectively navigate phase-selection and mechanical-properties predictions, developing aluminum-containing RHEAs in single-phase ordered B2 alloys demonstrating both high strength and ductility. These aluminum-containing RHEAs achieve remarkable mechanical properties, including compressive yield strengths up to 1.6 GPa, fracture strains exceeding 50 percent, and significant high-temperature strength retention. They also demonstrate a tensile yield strength of 1.1 GPa with a tension ductility of 6.3 percent. Besides, we identify a valence-electron-count domain for alloy brittleness with the explanation from density-functional theory and provide crucial insights into elements' influence on atomic ordering and mechanical performance. The work sets forth a strategic blueprint for high-throughput alloy design and reveals fundamental principles that govern the mechanical properties of advanced structural alloys.