Some Unique Aspects of Mechanical Behavior of Metastable Transformative High Entropy Alloys

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2021-03, Vol.52 (3), p.889-896
• Main Authors: Mishra, R. S., Nene, S. S.
• Format: Article
• Language: English
• Subjects: Alloy development; Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystal structure; Deformation mechanisms; Ductility; Engineering; Enthalpy; Evolution; Fatigue strength; Friction; Grain boundaries; High entropy alloys; High temperature; Innovations in High Entropy Alloys and Bulk Metallic Glasses in Honor of Peter K. Liaw; Materials fatigue; Materials Science; Mechanical properties; Metal fatigue; Metallic Materials; Metallurgy; Nanotechnology; Plastic deformation; Plastic properties; Structural Materials; Surfaces and Interfaces; Thin Films; Topical Collection: Innovations in High Entropy Alloys and Bulk Metallic Glasses
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-021-06138-3

This short review paper examines the uniqueness of metastable high entropy alloys (HEAs) that transform during plastic deformation. The linkages among alloy design induced metastablilty, processing induced “high enthalpy states” and evolving deformation micromechanisms are intriguing. One key aspect is the adaptive nature of deformation mechanisms because of activation of different micromechanisms during plasticity. This activation of deformation micromechanisms is attributed to transformation-induced plasticity in γ -f.c.c. phase and the evolving nature of c / a ratio in the ε -h.c.p. phase during deformation. As a result, metastable HEAs have good strength-ductility synergy and exceptional fatigue strength.