Year: 2026
Type: article
Abstract: Over the past decade, eutectic high-entropy alloys (EHEAs) with FCC and B2 phases have shown outstanding performance as advanced structural materials. Extensive efforts within the metallurgy community have established the thermodynamics-guided paradigm for eutectic synthesis. Here, we open a new frontier in physical metallurgy by exploiting carbon as a kinetic activator of eutectic solidification in EHEAs. Even trace carbon additions profoundly modified the eutectic transition, transforming hypereutectic structures into fully coupled FCC/B2 eutectics. With increased concentrations, carbon further induced decoupled FCC/B2 growth followed by a secondary FCC/carbide eutectic transformation, resulting in separated FCC and B2 dendrites together with high-density nanoscale M7C3 carbides. Multi-scale analyses reveal that carbon interstitials and carbides play an intriguing role in accelerating the nucleation kinetics. Across a broad range of additions, the tailored microstructures imparted an exceptional strength-ductility synergy in EHEAs. We found that interstitial carbon significantly enhanced dislocation storage and promoted the coordination of multiple slip modes, while the FCC/M7C3 nano-eutectics formed under high carbon content constructed a unique mechanical transition layer for global co-deformation. These discoveries establish “carbon engineering” as a powerful, kinetics-based strategy for EHEA design, pioneering new directions in advanced eutectic materials research.
Source: The Innovation Insights
Topic: High Entropy Alloys Studies
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7214945381