|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||Shape Memory Effect in the CrMnFeCoNi Alloy System
||Je In Lee, Koichi Tsuchiya, Wataru Tasaki, Hyun Seok Oh, Takahiro Sawaguchi, Hideyuki Murakami, Eun Soo Park
|On-Site Speaker (Planned)
||Je In Lee
High-entropy alloys (HEAs), which consist of multi-principal elements with near equiatomic composition, have generated substantial interest for the development of new materials with exceptional properties. Here, we demonstrate a strategy of designing HEAs with shape memory effect in the CrMnFeCoNi alloy system. We calculate the difference in Gibbs free energy between face-centered-cubic and hexagonal-close-packed phases, and find a substantial increase in thermodynamic equilibrium temperature between both phases through composition tuning, leading to thermally- and stress-induced martensitic transformations. Shape recovery temperature in non-equiatomic CrMnFeCoNi HEAs can be increased to 698 K, which is much higher than that of conventional shape memory alloys (SMAs) and comparable to that of B2-based multicomponent SMAs containing noble metals (Pd, Pt, etc.) or refractory metals (Zr, Hf, etc.). This result opens a vast field of applications of HEAs as a novel class of cost-effective high-temperature SMAs.