Phase-Transformation Ductilization of Brittle High-Entropy Alloys via Metastability Engineering

5 years ago

Phase-Transformation Ductilization of Brittle High-Entropy Alloys via Metastability Engineering

Wei Wu, Hui Wang, Xiongjun Liu, Junyang He, Zhaoping Lu, Ke An, Yuan Wu, Hailong Huang

High-entropy alloys (HEAs) in which interesting physical, chemical, and structural properties are being continuously revealed have recently attracted extensive attention. Body-centered cubic (bcc) HEAs, particularly those based on refractory elements are promising for high-temperature application but generally fail by early cracking with limited plasticity at room temperature, which limits their malleability and widespread uses. Here, the “metastability-engineering” strategy is exploited in brittle bcc HEAs via tailoring the stability of the constituent phases, and transformation-induced ductility and work-hardening capability are successfully achieved. This not only sheds new insights on the development of HEAs with excellent combination of strength and ductility, but also has great implications on overcoming the long-standing strength–ductility tradeoff of metallic materials in general. The “metastability-engineering” strategy is exploited in brittle body-centered cubic high-entropy alloys (HEAs) via tailoring the thermal and mechanical stability of the constituent phases, and consequently, transformation-induced ductility and work hardening capability are successfully achieved. This not only has important implications for developing high-performance HEAs, but also sheds light on overcoming the long-standing strength–ductility tradeoff of metallic materials in general.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701678