Abstract
This study experimentally investigates the effects of thermal treatment on the elastocaloric effects and transformation behavior of superelastic Ni-Ti alloys, with the aim of developing eco-friendly green cooling technologies as an alternative to conventional methods. We focused on tube-shaped superelastic Ni50.8Ti49.2 (at.%) alloy, observing that short-time aging at 400°C resulted in improved mechanical properties and enhanced elastocaloric effects. It was suggested that these changes in the properties of the Ni-Ti alloy are primarily due to the precipitate morphology of Ni4Ti3 nanocrystals in the NiTi single phase, which significantly impacts the transformation temperature defining cooling performance. The ability to manipulate the austenite finish (Af) temperature range, as evidenced in our findings, suggests potential for the development of cascade elastocaloric cooling systems through thermal treatment of a single composition Ni-Ti alloy. This study underscores the potential of Ni-Ti based superelastic shape memory alloys for future environmentally-friendly cooling applications.
