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Shape memory alloy has a variety of characteristics, so its application is also more extensive, the following selected some typical applications for detailed description.
(1) Fabrication of space antenna with shape memory alloy based on nickel titanium. The antenna is mainly made by using its shape memory effect. The antenna is deformed and loaded into the carrier at normal temperature. After entering the space environment, the antenna is heated back to its original shape set on the ground by using solar radiation or other heat energy.
(2) pipe joints. Shape memory alloy pipe joint is mainly used in oil pipeline and other aspects, the ordinary welding operation is difficult, and the sealing is poor, but the shape memory alloy can not only use the shape memory effect to connect the pipeline, easy to operate, good sealing, its own corrosion resistance, excellent wear resistance, more competent for this kind of work.
(3) Fire alarm. The memory alloy element is set to a corresponding shape at a specific temperature. In case of fire, the alloy will be restored to its original state to drive other elements to work and carry out fire alarm and positioning. This method has the advantage that it does not need other driving energy to supply the normal temperature sensor, which is more stable.
(4) micro-manipulator manufacturing. Shape memory alloy can convert the temperature change into action, and its role in the manipulator is similar to that of the muscle in the human arm.
The temperature change is controlled by controlling the current on and off to control the extension of the alloy
This kind of manipulator structure is more concise, compact, good simulation, but the work may be affected by the external environment temperature.
(5) memory alloy engine. This device is of great significance for the recovery and utilization of low quality energy (such as cooling water). In the experiment, different memory alloy chains were used.
The parts are placed in warm water and cold water at the same time, so as to generate telescopic force, which drives other parts to do work. Achieving this low quality energy utilization.
(6) Orthodontic silk. Most memory alloys used in the biomedical field are nickel-titanium alloys because of their non-toxic, low toxicity, corrosion resistance and good biocompatibility. With hyperelastic materials commonly used while for orthodontics silk, super elastic material elastic range is very large, and because of his strength and material bending degree is not a linear relationship, in the case of bending degree have change, orthodontic force will not change is too big, and ordinary material, not only for the demand of the medical operation difficulty is higher, but also for patients with poor compared to the comfort of hyperelastic materials also.
(7) vibration eliminator. For general vibration suppression materials, when the vibration suppression effect is good, the strength is often low, which is often unable to have both, and shape memory alloy is not only good vibration suppression effect, but also high strength, compared with other materials have obvious advantages.
In recent years, the research and application of memory alloys have developed rapidly, such as the application of nickel-titanium base alloys in medical orthopedics, the research of thin film shape memory alloys and the application of memory alloys in wings with variable thickness. However, the development path of shape memory alloy is not always smooth. The following obstacles are listed: (1) Nickel titanium alloy is often used in biomedical science. Although it has good biocompatibility and non-toxic and low toxicity, it cannot guarantee absolute safety to human body, and further study is needed in the treatment safety. ② The repeated positive reversal of martensite will inevitably lead to material damage. How to reduce the damage in the process of phase transformation and improve the fatigue life of materials is a subject worth studying.
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