Shape-memory alloys are capable of undergoing reversible phase transitions as a result of temperature, pressure, or other stress-related changes. These materials exhibit a mechanical type of shape memory called pseudoelasticity and, under certain conditions, linear superelasticity. The recoverable strain or shape is generally . Whereas the alloys are primarily nonferrous, some ferrous alloys also exhibit shape memory. Applications of shape-memory alloys include those as tubes and valves in piping systems for power plants, ships, and the petroleum industry; use as explosive bolts in the aerospace and construction industry; as packaging devices for electronic materials; and as dental materials, prosthetics, and biomedical devices. Shape-memory alloys may be found in sensors in automobiles, in consumer products, and generally in smart materials and adaptive structures.