Shape memory alloy (SMA) is a kind of material which has shape memory effect according to thermal ductility, austenite change and inverter power supply. Shape memory alloy is the best shape memory material in shape memory materials. So far, we have found that there are more than 50 kinds of aluminum alloys with shape memory effect. There are many successful cases in aerospace industry. The giant wireless antennas on man-made earth satellites can be made of memory alloy. Before sending the man-made earth satellite, the paraboloid antenna is retracted and put into the communication satellite body. After the rocket takes off to send the artificial earth satellite to the reserved track, it only needs to heat up. The retractable satellite antenna can naturally repair the paraboloid shape because of its memory function.



Ordinary metal materials have no shape memory. If they sit on aluminum frames and bend them permanently, they can't return to their original shape. You must be hard to adjust the appearance of the spectacle frame in your own memory, even if it is, there is no way to ensure that the spectacle frame returns to its original appearance. And if the frequency of round-trip bending is too much, the glasses frame will always be broken if it reaches the fatigue limit.



Shape memory alloy is different from ordinary metal materials. They are strong and light aluminum alloys with unique properties. They can program and remember the original shape, so if they are bent or extruded, they can be restored to their original shape again according to the heating. This is called the shape memory effect. Some shape memory metal materials remember one shape when they are hot, but another when they are cooled, so they change into one shape when they are cooled, but when heated, they forget the original shape and shrink to a different shape. This is called the double shape memory effect.



Shape memory alloy (SMA) is an aluminum alloy material with shape memory effect, which is generally composed of two or three rare elements. The exhibit shows the memory effect of dual memory alloy materials, which show one shape when heated and another shape when cooled. During the whole deformation process, the change of thermal ductility austenite is the direct cause of memory effect. This kind of material has many excellent properties, and is widely used in aerospace, mechanical automation, biomedical, bridge construction, automobile industry and living and other industries.