めっき技術

Ni-Ti (shape-memory alloys)

Shape-memory alloys are distinct alloys which can be easily transformed and restored in shape with heat. As an application example, an antenna is brought into space as it is folded into a small piece at low temperature (a), which is heated by solar heat in space, and is restored to a large antenna shape in memory (d). This shape-memory mechanism is based on the thermoelastic martensitic transformation in alloys.
Type Features Uses
[1] Gold-cadmium alloy
[2] Indium-titanium alloy
[3] Nickel-titanium alloy
[4] Copper-aluminum-nickel alloy
[5] Copper-zinc alloy
[6] Copper-zinc-x alloy (x: aluminum, nickel, tin, silicon)
[7] Nickel-aluminum alloy
[8] Silver-cadmium alloy
[9] Copper-gold-zinc alloy
[10] Copper-tin alloy
nitisub.jpg
Schematic diagram of the mechanism of the shape-memory effect
(From “Kinzoku Benran” edited by the Japan Institute of Metals and Materials; Maruzen)
- [Space development]
Satellite antennas, lunar surface antennas

- [Various connection parts]
Pipe joints, rivets, connectors

- [Robots]
Actuators

- [Medical purposes]
Artificial hearts, micropumps for artificial hearts, etc.
採用事例
Ni-Ti (shape-memory alloys)
Space rocket antenna made of Ti-Ni alloy wire
(From Goodyear Aerospace Corp’s catalog)