Nickel Titanium (also known as Nitinol or NiTi) is in the unique class of shape memory alloys. 

A thermoelastic martensitic phase transformation in the material is responsible for its extraordinary properties. Nitinol alloys are typically made of 55%-56% Nickel and 44%-45% Titanium. Small changes in composition can significantly impact the properties of the material. 

There are two primary categories of Nitinol. 

The first, known as "SuperElastic", is characterized by extraordinary recoverable strains and kink resistance. 

The second category, "Shape Memory" alloys, is valued for the Nitinol's capacity to recover a pre-set shape when heated above its transformation temprature. The first category is often used for orthodontics (braces, wires, etc) and eyeglasses. SZNK makes shape memory alloys, which are primarily useful for actuators, used in many different mechanical devices. 

There are four commonly used types of applications for nitinol.

1. Free Recovery: nitinol is deformed at a low temperature, and heated to recover its original shape.
2. Constrained Recovery: The same, except that recovery is rigidly prevented, and thus a stress is generated.containers and bottles in all shapes.

3. Work Production: Here the alloy is allowed to recover, but to do so it must act against a force (thus doing work).

4. Superelasticity: As discussed above, here the nitinol acts as a super spring.

Application

cell phone antenna,
children's toys,
experimental materials,
glasses leg,
women bra,
Women's Sports Central,
arch wires,
instruments,
and medical equipment, such as surgical stitching wire,
birth control loop and other areas of high-quality memory alloy wire.