shape memory alloy

Shape Memory Alloy (SMA)

An alloy that 'remembers' its original shape and returns to it when heated.

Austenite Phase

The high-temperature phase of a shape memory alloy characterized by a body-centered cubic (BCC) structure.

Martensite Phase

The low-temperature phase of a shape memory alloy that can be deformed when cold.

Thermo-mechanical behavior

The response of materials to thermal and mechanical conditions, particularly important in SMAs.

Transformation Temperature

The temperature at which the phase transformation between martensite and austenite occurs.

Superelasticity

A behavior of SMAs whereby they can undergo significant deformation and return to their original shape upon unloading.

One-way Shape Memory Effect

When a shape memory alloy holds deformation until heated above the transformation temperature, then returns to its original shape.

Two-way Shape Memory Effect

When a shape memory alloy remembers two shapes, one at high temperature and one at low temperature.

Copper-Aluminium-Nickel Alloy

A prevalent type of shape memory alloy known for its shape memory characteristics.

NiTi Alloy (Nitinol)

A commonly used shape memory alloy made from nickel and titanium, known for its stability and performance.

Copper-Zinc-Sn Alloy

A specific type of copper-based shape memory alloy composed of copper, zinc, and tin, with various applications.

Phase Transformation

The reversible change in structure between different phases, crucial for the shape memory effect.

Hysteresis

The difference between transformation temperatures upon heating and cooling in SMAs.

Memory Metal

Another term used to refer to shape memory alloys due to their ability to return to a preset shape.

Damping Properties

The ability of SMAs to absorb energy during deformation and return to their original state without damage.

Thermal Stability

The capability of an alloy to maintain its shape memory properties over extended periods at elevated temperatures.

Applications of SMAs

Include uses in medical devices, actuators, robotics, aerospace components, and civil structures.

Copper-Aluminium-Nickel Alloys (Cu-Al-Ni)

A type of shape memory alloy characterized by a moderate temperature range for transformation.

Brittleness

A material property that can hinder the performance of certain shape memory alloys, particularly in fabrication.

Actuator

A device that uses energy to create motion, where SMAs serve as a lightweight alternative.

Cryo-electronics

An emerging field where shape memory alloys can be applied to control devices at cryogenic temperatures.