A eutectic high-entropy alloy with good high-temperature strength-plasticity balance

• Main Authors: Liuliu Han, Xiandong Xu, Li Wang, Florian Pyczak, Rui Zhou, Yong Liu
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2019-11-01
• Series: Materials Research Letters
• Subjects: eutectic high-entropy alloy; compression behavior; strain hardening; strength-plasticity balance
• Online Access: http://dx.doi.org/10.1080/21663831.2019.1650130

We developed a eutectic high-entropy alloy (EHEA) with appreciable high-temperature strength-plasticity balance. Structural characterizations of the as-cast sample revealed a lamellar structure with austenite (face-centered-cubic, FCC) and Laves phases. Upon annealing at 873 K, precipitation of nanoscale (Ni, Al, and Zr)-rich L12 phase from the FCC phase took place, which eventually transformed into a martensitic (hexagonal, ε) phase with rearrangement of atomic species. Compressive properties revealed a brittle behavior at temperatures below 873 K, but changed to a ductile behavior with considerable strain hardening at 973 K, due to the formation of a high density of deformation twins observed by transmission electron microscopy.