A lightweight shape-memory alloy with superior temperature-fluctuation resistance

Abstract In advanced applications such as aerospace and space exploration, materials must balance lightness, functionality and extreme thermal fluctuation resistance 1,2 . Shape-memory alloys show promise with strength, toughness and substantial strain recovery due to superelasticity, but maintaining low mass and effective operation at cryogenic temperatures is challenging 3–6 . We hereby introduce a new shape-memory alloy that adheres to these stringent criteria. Predominantly composed of Ti and Al with a chemical composition of Ti 75.25 Al 20 Cr 4.75 , this alloy is characterized by a low density (4.36 × 10 3 kg m − 3 ) and a high specific strength (185 × 10 3 Pa m 3 per kg) at room temperature, while…