Features of memory alloys were discovered in the early 1950s, and gold, cadmium, indium, and thallium alloys all have these characteristics.

Memory alloys have been used for pipeline connection and automation control. A shell made of memory alloy can replace welding. The method is to expand the tube end by about 4% at low temperature. The sleeves are put together during assembly. Once heated, the sleeve shrinks back to its original shape, forming a tight connection. The Navy ’s aircraft ’s hydraulic system uses 100,000 of these connectors and has not leaked or been damaged for years. It is very convenient to repair damaged ships and subsea oilfield pipelines with memory alloy accessories. In some inconvenient places, make memory alloy pins and heat them into holes. The trailing end of the pin is automatically separated and curled to form a single-sided assembly.

Memory alloys are particularly suitable for thermomechanical and constant temperature automatic control. Automatically opened and closed arms at room temperature. It can open the ventilation window on sunny days and automatically close when the room temperature drops at night. There are many designs for memory alloy heat engines, which can work between two low temperature difference media, thus opening up new ways to use industrial cooling water, nuclear reactor waste heat, ocean temperature difference and solar energy. The current problem is that the efficiency is not high, only 4% -6%, and needs to be further improved.

Memory alloys have also attracted considerable attention in medical applications. For example, a bone graft can not only fix two broken bones, but also generate compressive forces during the restoration process, forcing the broken bones together. Orthodontic steel wires, cerebral aneurysms, long clips for vas deferens and support plates for spine correction are all activated by body temperature after implantation. The thrombosis filter is also a new memory alloy product. After the corrected filter paper was implanted in the vein, the filter paper gradually returned to a net shape, preventing 95% of blood clots from flowing into the heart and lungs.

Artificial heart is a kind of complex structure. The muscle fibers made of memory alloy match the elastic membrane ventricles to simulate ventricular contractions. The pumping is now successful.

As the memory alloy is a kind of "living alloy", various automatic control devices can be designed by using its shape change at a certain temperature, and its application range is continuously expanded.