Ni-Ti shape memory alloy is particularly suitable for thermomechanical and constant temperature automatic control. It can be made into an automatic opening and closing arm at room temperature. It can open the ventilation window during the day when the sun is shining and close automatically when the room temperature drops at night. There are also many design schemes of memory alloy heat engines. They can work between two media with low temperature differences, thus opening up new ways to use industrial cooling water, nuclear reactor waste heat, ocean temperature difference and solar energy. A common problem now is that the efficiency is not high, only 4% to 6%, which needs to be further improved.
Nickel-titanium shape memory alloys have been used for pipe bonding and automation control. Casings made of memory alloys can be used instead of welding. The method is to expand the inside of the pipe end by about 4% at low temperatures, and to socket together during assembly. Once heated, The sleeve shrinks back to its original shape, forming a tight joint. Ships and subsea oilfield pipelines are damaged, and it is very convenient to repair them with memory alloy accessories. In some inconvenient construction sites, pins are made of memory alloy and heated in the holes. The tail ends are automatically separated and curled to form a single-sided assembly.
Ni-Ti shape memory alloy is widely used in medical applications. For example, bone plates for osteosynthesis, orthodontics for dental use, long clips for ligation of cerebral aneurysms and vas deferens, and branch plates for spinal straightening, etc. are all activated by body temperature after being implanted in the body. It is also a new memory alloy product. When the straightened filter is implanted in a vein, it gradually returns to a mesh, preventing 95% of the clot from flowing to the heart and lungs. Artificial heart is a kind of organ with more complicated structure. The muscle fiber made of memory alloy is matched with elastomer membrane ventricle, which can imitate ventricular contraction movement. Pumping water is now a success.
