Nitinol wire is a metal alloy, sometimes also called Shape Memory Alloy (SMA) wire.
Nitinol is an example of a "smart" material that undergoes changes between two solid phases, called the austenite and martensite phases, that involve rearrangement of its atoms within its crystal lattice. Nitinol is unusual in that it "remembers" its shape because the its crystal structure arrangement is not changed during a phase change.

Tempers:
Our Nitinol wire products can be produced to engineered mechanical properties designed for your end use and manufacturing processes.

Superelastic and Shape Memory available Transformation Temperatures:
Custom Alloy Formulations Possible.

Nitinol Fundamentals:
Nitinol is a nickel-titanium alloy distinguished from other materials by its shape memory and superelastic characteristics.
Nitinol wire is the most mature form of this unique superelastic and shape memory alloy, It is available in many different sizes, alloys and finishes. And, shape memory and superelastic forms are both offered. Niti shape memory alloys are gaining increasing use in the medical device industry for Nitinol catheter stents, guidewires and other critical applications.

Physical Properties of Nitinol:
Density: 6.45gms/cc
Melting Temperature: 1240-1310° C
Resistivity (hi-temp state): 82 uohm-cm
Resistivity (lo-temp state): 76 uohm-cm
Thermal Conductivity: 0.1 W/cm-° C
Heat Capacity: 0.077 cal/gm-° C
Latent Heat: 5.78 cal/gm; 24.2 J/gm
Magnetic Susceptibility (hi-temp):3.8 uemu/gm
Magnetic Susceptibility (lo-temp): 2.5 uemu/gm

Mechanical Properties of Nitinol:
Ultimate Tensile Strength: 754 - 960 MPa or 110 - 140 ksi
Typical Elongation to Fracture: 15.5 percent
Typical Yield Strength (hi-temp): 560 MPa, 80 ksi
Typical Yield Strength (lo-temp): 100 MPa, 15 ksi
Approximate Elastic Modulus (hi-tem): 75 GPa, 11 Mpsi
Approximate Elastic Modulus (lo-temp): 28 GPa, 4 Mpsi
Approximate Poisson's Ratio: 0.3

Actuation:
Energy Conversion Efficiency: 5%
Work Output: ~1 Joule/gram

Shape Memory Alloys Description:
The term Shape Memory Alloys (SMA) is applied to a group of metallic materials that demonstrate the ability to return to some previously defined shape or size when subjected to the appropriate thermal procedure. Generally, these materials can be plastically deformed at some relatively low temperature, and upon exposure to some higher temperature they will return to their shape prior to the deformation.