How are shape memory alloys different from ordinary alloys?

Shape memory alloys are materials composed of two rare elements that have shape memory effects based on thermal ductility, austenite variation, and inverter power. Shape memory alloy is one of the better shape memory materials at present. So far, 50 kinds of aluminum alloys have been found to have many shape memory effects. There are many successful applications in the aerospace industry. Giant wireless antennas on Sputnik can be made from memory alloys. Before launching the satellite, the parabolic antenna is put into the body of the communications satellite, and then the rocket lifts the satellite into orbit, and then heats it up. The telescopic antenna has memory function, and of course the parabolic shape can be repaired.

Ordinary metal materials have no shape memory. If they sit on an aluminum frame and bend permanently, they will not regain their original shape. You must work hard to adjust the framework. Even then, there is no guarantee that the framework will be the same as before. If they bend back and forth too often, the glasses reach their fatigue limit and they will always break.

Shape memory alloys and common metal materials mainly behave differently. They are strong and light aluminium alloys with unique properties. They can be programmed to remember their original shape, so if they are bent or squeezed, they can be heated so that they can return to their original shape again. This is called the shape memory effect.

Metals remember one shape when they are hot and another when they are cold, so when they are cold they change into one shape, but when they get hot they forget their original shape and shrink into another. This is called the double shape memory effect.

Shape memory alloy is a kind of aluminum alloy material with shape memory function. It usually consists of two or three rare elements. The exhibits demonstrate the memory effect of a dual memory alloy, which takes on one shape when heated and returns to another shape when cooled. The change of thermal expansion austenite in the material is the direct cause of the memory effect. These materials have many excellent properties and are widely used in aerospace, mechanical automation, biomedicine, bridge construction, automobile industry and daily life, etc.