Ti-Ni alloy memory wire is widely used
Due to its super-elasticity and recoverability, Ti-Ni alloy memory wire has served in many fields such as biomedicine, aerospace, daily life and mechatronics.
(1) Biomedical Applications: TiNi shape memory alloy for medical applications, in addition to its shape memory effect or superelasticity, should be satisfied with the needs of the chemical and biological aspects, that is, good biocompatibility. TiNi and organisms can form a stable passive film. At present, the primary use of TiNi alloy wire in medicine is:
() orthodontic wire Tooth correction wire made of surrealistic TiNi alloy wire and stainless steel wire, in which super-elastic TiNi alloy wire is most suitable. Stainless steel wire CoCr alloy wire is usually used for orthodontics, but these materials have defects of high elastic modulus and small elastic strain. In order to provide a suitable corrective force, it is machined into a bow before correction, and the need for ligation fixation is good. If a TiNi alloy is used for the orthodontic wire, plastic deformation will not occur even if the strain is as high as 10%, and stress-induced martensite causes the elastic modulus to exhibit non-linear characteristics, that is, when the strain increases Corrective force shaken very little. This raw material is not only simple operation, good effect, but also reduces discomfort in patients.
(b) Scoliosis Orthotics Various scoliosis conditions (congenital, habitual, neurological, rickets, idiopathic, etc.) diseases are not only severely damaged by physical and mental problems, but also visceral is squeezed, so it is necessary surgical orthosis. The current selection of stainless steel surgical Harrington rod orthopedic surgery orthopedic bar placement, the demand for fixation of the spine was maintained below 30-40kg, but the force is too large, the orthopedic rod will be damaged, the results Not just the spine, but also nerve damage. With the existence of orthopedic rods placed corrective corrective power will change at any time, about the correction of power down to 30% of the initial time, the need for further surgical correction to correct the power to the patient so that the formation of great pain and physical. Harrington rods made of shape memory alloy are used for orthopedic rod fixation. If corrective force orthopedic rod changes, to shape the alloy by heating the body after the recall, the temperature is raised to about 5 higher than body temperature, you can recover to meet the correction. In addition, the surgical use of TiNi shape memory alloy made of various bone adapters, vascular clamps, coagulation filters, and vascular expansion components. Together also widely used in stomatology, orthopedics, cardiovascular, thoracic, hepatomegaly, urology, gynecology, etc., with the shape memory, medical application will be more extensive.
(2) Use in Aerospace Industry: Shape Titanium-nickel alloy memory alloy has been applied to aviation and space equipment. For low-temperature cooperation in hydraulic systems used in military aircraft, Europe and the United States are developing shape memory alloy materials used in the helicopter's intelligent horizontal rotor. Because of the high helicopters sense and the use of high noise is limited, the noise and the sense of the first and foremost vortex turbulence interference, as well as the blade profile of small errors. This requires a device that balances the blade pitch so that each blade can rotate exactly on the same plane. It has now been announced that a leaf rail manipulator that uses a small dual-tube shape memory alloy actuator to manipulate the orientation of the widget on the marginal orbit of the blade minimizes its sense. Can also be used to make the lunar antenna to explore the mysteries of the world, we use the shape memory alloy in the high temperature environment to make a good antenna, and then compressed at low temperatures into a small iron ball, so that its volume reduced to one thousandth of the original , It is very easy to get on the moon, the sun's intense radiation to make it recover the original shape, in accordance with the needs of the Earth back to the precious world of information. In addition, a shape memory release device is used in satellites to open the container for maintenance of an active germanium detector from contamination of the mounting and firing time.
(3) Daily life use:
(A) anti-scald valves on family days, shape-recall valves have been developed to prevent accidental scalding of hot water in tubs, baths and bathrooms; these valves can also be used in hotels and other suitable places. If the temperature of the faucet reaches a temperature that can burn people 48 C), the shape memory alloy actuates the valve to close until the water temperature drops to a safe temperature and the valve opens again.
(B) Eyeglass Construction The TiNi alloy in the nose and ears of the eyeglass structure provides comfort and abrasion resistance because the flexibility of TiNi alloys has made them widely used to modify the eyewear industry. With super-elastic TiNi titanium alloy wire glasses structure, even if the lens thermal expansion, the shape memory alloy wire can also super-elastic constant force of the lens. The deformation of glass made of these surrealistic alloys can be great, but the general glasses frame cannot do so.
(C) Mobile Phone Antenna and Fire Viewing Valve using a hyperelastic TiNi wire as a Cell Phone Antenna is another use of shape memory alloys. Previously used stainless steel antenna, because the twists and turns often present the problem of damage. The use of TiNi shape memory alloy wire mobile phone antenna, with high resistance to damage by everyone over the book. It is thus commonly used to make cellular telephone antennas and fire inspection valves. In the event of a fire, the valve will automatically close when warmed in some places, avoiding the possibility of gas entering. The advantage of this special construction plan is that it has the function of looking at the valve and then resetting it to a harmless condition. This fire inspection valve is used in the semiconductor manufacturing industry and uses toxic gas in the dispersion process of semiconductor manufacturing. This fire inspection valve can be used in chemical and petroleum plants.
(4) The use of mechanical and electronic products: In 1970, the United States used a shape memory alloy to make the low-temperature cooperation connector on the F-14 battle, followed by the use of millions of pieces. As the low-temperature cooperation, the shape memory alloy is employed in the hydraulic system of the aircraft and the smaller-sized petroleum, petrochemical and electrical products. The other form of engagement member is a welded mesh wire used to carry out a secure joint of wire woven layers of conductors. This connector is now used for sealing equipment, electrical connection equipment, electronic engineering machinery and equipment, and reliable operation at 65 ~ 300. Sealing system has been opened equipment can be used in strict electrical environment convergence. The shape memory alloy made of a shutter can open and close the spring, used to maintain the fog light from flying debris damage. For the production of fine instruments or precision lathe, once because of the sensational, bump and other causes of deformation, just heating can be troubleshooting. In the mechanical production process, a variety of stamping and mechanical operations often need to transfer parts from one machine to another machine, and now the use of shape memory alloy developed a replacement manual or hydraulic fixture, this device is called the cylinder, It has high efficiency and sensitivity, clamping force and other characteristics.
