Nitinol

Description

A tradename for a Shape memory alloy (SMA) that can be deformed then return to its original shape with heat. Nitinol was developed in the 1950s by William Buehler at the U.S. Naval Ordinance Laboratory. The alloy is composed of Nickel (55%) and Titanium (45%). Its name is an acronym for Nickel-Titanium Naval Ordinance Lab. Shape-memory materials take advantage of phase transformations; Liquid to solid or liquid to gas transitions are widely know but changes can also occur with solid phases when the atoms or molecules that make up a material adopt a different pattern. In Nitinol, the phase change is just above room temperature. One example shows a crumpled spoon spring back to its original shape when placed in a cup of warm water. Less expensive shape memory metals are composed of copper-zinc-aluminum alloys.

Synonyms and Related Terms

shape memory alloy (SMA); memory metal; smart wire; Nitionol (Deut.)

Resources and Citations

• Nitinol: Website
• Confluent Medical: Nitinol Facts
• Cosmos Magazine: Metal with a memory
• Wikipedia: Shape-memory alloy accessed October 2024