Iron and Nitinol-based high-entropy shape memory alloys: A comprehensive review of advances and critical perspectives

This review provides a comprehensive synthesis of High-Entropy Shape Memory Alloys (HESMAs), a revolutionary class of intelligent materials. By unifying Fe-based and NiTi-based multi-component systems within a single comparative framework, this work highlights the transformative potential of high-entropy alloying and additive manufacturing to bridge traditional metallurgy and smart material design. The study systematically evaluates functional characteristics, including fatigue resistance, damping capacity, and biocompatibility, alongside advanced processing routes such as power metallurgy, spark plasma sintering, and mechanical alloying. Novel contributions include a quantitative synthesis of transformation behaviors and a forward-looking roadmap integrating AI-assisted design and standardized testing. By addressing critical gaps in scalability and cost, this review positions HESMAs as versatile candidates for next-generation aerospace, biomedical, and infrastructural applications, establishing a clear trajectory for future research in the field. This trajectory not only highlights the potential of HESMAs but also encourages interdisciplinary collaboration to unlock their full capabilities. As researchers continue to innovate and refine these materials, they can expect significant advancements that may revolutionize various industries, ultimately enhancing performance and sustainability.