| Abstract Scope |
Shape memory alloys (SMAs), such as Nickel-Titanium, are multifunctional materials, which have the ability to recover a designed shape upon heating. While binary NiTi SMAs are limited to a maximum austenite finish temperature of 115°C, high temperature SMAs (HTSMAs), such as NiTiHf and NiTiZr, have much higher transformation temperatures that can be tuned for specific applications, which makes them attractive candidates for many aerospace, and energy applications. NiTiHf and NiTiZr have been found to be difficult to process due to the formation of oxides that exacerbate the already brittle nature of the material. In this study, the effect of Ni content in Ni-rich NiTiHf HTSMAs on processability, microstructure, and hardness was analyzed for three compositions. Each composition was characterized in three conditions: homogenized, 25%, and 50% thickness reduction through hot-rolling. Differential scanning calorimetry, scanning electron microscopy, energy dispersive spectroscopy, and Vickers hardness testing were utilized to characterize the resulting materials. |