Low Temperature Shape Memory Alloys Development for Actuation at Cold Temperatures

Substantial efforts in the last decade have been dedicated to developing viable shape memory alloys (SMAs) for use as solid-state actuators at temperatures above 100 °C. This work has resulted in several breakthroughs in both material development, processing and applications. While these alloys are being scaled-up and matured, interest is just developing in the counterpart low-temperature shape memory alloys (LTSMAs). The LTSMAs can yield several benefits in the aerospace arena, but they have not been examined rigorously. Aero-structural and space solutions such as aerodynamic surfaces of aircrafts (e.g., vortex generators, strakes, engine chine), deep-space devices (e.g., adaptive radiators, pointing mechanisms), and structural superelastic applications (e.g., planetary rover tires, landing systems), amongst others, can all benefit from viable LTSMAs. In this work, several LTSMAs are examined in detail and compared not just by transformation temperatures down to -150 °C, but also by work output and actuation stability at temperatures down to -60 °C.