Microstructures, transformation temperatures and superelastic properties of the rapidly solidified (TiZrHf)50Ni25Co10Cu15 HESMAs

Abstract

In this study, the effects of the rapid solidification process on microstructures, transformation behaviors and superelastic properties of the multi-component (TiZrHf)50Ni25Co10Cu15 (at%) high-entropy shape memory alloy (HESMA) were investigated. The as-spun (TiZrHf)50Ni25Co10Cu15 fibers were prepared by a rapid solidification process. The solution-treated (TiZrHf)50Ni25Co10Cu15 alloy bulk specimen consisted of a (NiCoCu)-rich matrix, (TiZrHf)2(NiCoCu)-type phase and carbide, while the as-spun fiber specimen consisted of (TiZrHf)-rich matrix and carbide. The (TiZrHf)2(NiCoCu)-type phase is dissolved in the matrix of as-spun fibers due to the rapid solidification process. The martensitic transformation start temperature of the (TiZrHf)50Ni25Co10Cu15 alloy increased from 53.5 °C to 91.5 °C after the rapid solidification process. Both the (TiZrHf)50Ni25Co10Cu15 alloy bulk and fiber specimens showed clear superelasticity and the total superelastic recovery strain increased from 4.6 % to 5.7% after the rapid solidification process. © 2024 Elsevier Ltd