How much do you know about titanium-nickel alloy?
Nitinol is a shape memory alloy. Shape memory alloys are special alloys that can automatically restore their plastic deformation to their original shape at a specific temperature and have good plasticity.
In addition to its unique shape memory function, memory alloys also have excellent features such as wear resistance, corrosion resistance, high damping and superelasticity.
Performance and features
1,Phase transformation and properties of nickel-titanium alloy
As the name suggests, nickel-titanium alloy is a binary alloy composed of nickel and titanium. Due to changes in temperature and mechanical pressure, there are two different crystal structure phases, namely the austenite phase and the martensite phase. The phase transformation sequence of nickel-titanium alloy when cooled is parent phase - R phase - martensite phase. The R phase is rhombic, and austenite is the state when the temperature is higher or when the load is removed. It is cubic and hard. The shape is relatively stable. The martensite phase is a state at relatively low temperature or under loading. It is hexagonal, ductile, repeatable, less stable, and easier to deform.
2, Special properties of nickel-titanium alloy
Shape memory characteristics: Shape memory is when the parent phase of a certain shape is cooled from above the Af temperature to below the Mf temperature to form martensite, the martensite is deformed at a temperature below Mf, and heated to below the Af temperature, accompanied by reverse phase transformation. The material automatically returns to its original shape.
3,Classification of nickel-titanium alloy wire Evans and Durning classification method
⑴ In 1940, gold arch wire, cobalt-chromium alloy wire and stainless steel round wire
⑵ In 1960, martensitic stabilized alloys: mostly made of nickel-titanium alloys deformed in the martensitic state. This type of archwire has low stiffness and can produce lighter correction force.
⑶ In 1980, Chinese nickel-titanium alloy and Japanese nickel-titanium alloy archwires were austenite-activated alloys: that is, they showed an austenite state in any state and had no martensite caused by temperature when placed inside or outside the mouth. body status.
⑷In 1990, martensite-activated nickel-titanium alloy: that is, the TTR is lower than the oral temperature or very close to the oral temperature. It exists in a multi-element state at room temperature and is easy to deform.
⑸ Graded thermodynamic: Increased thermodynamic nickel-titanium alloy: The TTR temperature is higher than the oral temperature, about 40°C. In this way, when the nickel-titanium archwire is placed in the oral cavity, it is still in a multi-dimensional state and the archwire is relatively soft.
4, Application areas: used in superelastic memory alloy mobile phone antennas, fishing hooks, fishing rods, children's toy antennas, optical glasses frames, Bluetooth headsets, ear hooks, and medical. With the development of the times, it began to be gradually used in women's clothing rings and was used as scientific research material. It frequently appeared in the materials laboratories of various polytechnic universities.
5, Product characteristics: It has mechanical properties and corrosion resistance, and has a unique memory function that can restore the memory shape at the phase change temperature.
6, Product classification: temperature memory and elastic memory.
7, Advantages: Super memory, super elasticity, small size, light weight, low power, high strength, precise control, AC or DC activation, long life, linear motion.
Various parameters of titanium-nickel alloy memory wire:
Specifications: Diameter 0.1mm or more* coiled wire (straight wire)
Standard: Q/XB1516 Q/XB1520
Brand number:
TiNi-01 phase transition temperature: 20℃-40℃
TiNi-02 phase transition temperature: 45℃-65℃
TiNi-SS phase transition temperature: 5℃-15℃
TiNi-03 phase transition temperature: <5℃
TiNi-YY phase transition temperature: 33℃±3℃
TiNiCU phase transition temperature: As－Ms≤5℃ TiNiNb
Phase transition temperature: As-Ms<150℃
Physical properties of titanium-nickel alloy memory wire:
Tensile strength: 850 MPa Yield strength: 195～690 MPa Elongation: 25～50%
Chemical composition: Ni:55.4% --56.2% C≤0.07 H≤0.005 O≤0.050 N:≤ 0.05
Implementation standard: ASTM-2063-01 ASTM F2063-2000 Shape memory alloy processing materials The so-called memory metal refers to a series of metals and alloys with "memory".
After this kind of memory metal is deformed, it can be restored to its previous state under certain external effects, such as high pressure, high temperature, low temperature, electricity and other special conditions. Memory metal has a wide range of applications, and all its properties change with temperature changes. From a microscopic perspective, the atoms of memory metals (metals are made of atoms, not ions or molecules) have a unique spatial structure. After external forces change their macroscopic shape, under certain conditions, their spatial structure may change. Will reply.
