How much do you know about such a great nickel-titanium alloy?

Original title: How much do you know about such a great nickel-titanium alloy? NiTi alloy is a kind of shape memory alloy. Shape memory alloy is a special alloy which can automatically restore its original shape at a specific temperature after plastic deformation. Its expansion ratio is more than 20%, its fatigue life is up to the seventh power of 1 × 10, its damping characteristic is 10 times higher than that of ordinary springs, and its corrosion resistance is superior to that of the best medical stainless steel at present, so it can meet the needs of various engineering and medical applications, and it is a very excellent functional material. In addition to the unique shape memory function, shape memory alloy also has the excellent characteristics of wear resistance,nickel titanium wire, corrosion resistance, high damping and superelasticity. Now, let’s summarize the seven special properties of nickel-titanium alloys: 1. Shape memory characteristics: Shape memory is that when the parent phase of a certain shape is cooled from above Af temperature to below Mf temperature to form martensite, the martensite is deformed below Mf temperature,titanium seamless tube, and then heated to below Af temperature, accompanied by reverse phase transformation, the material will automatically restore its shape in the parent phase. In fact, the shape memory effect is a thermally induced phase transformation process in NiTi alloys. 2. Hyperelasticity: The so-called hyperelasticity refers to the phenomenon that the sample produces a strain far greater than the elastic limit strain under the action of external force, and the strain can be automatically restored when unloaded. That is to say, nickel titanium wire ,titanium bar gr7, in the parent phase state, due to the external stress, the stress-induced martensite transformation occurs, so the alloy shows different mechanical behavior from ordinary materials, its elastic limit is far greater than that of ordinary materials, and it no longer obeys Hooke’s law. Expand the full text 3. Corrosion resistance: Studies have shown that the corrosion resistance of nickel-titanium wire is similar to that of stainless steel wire. 4. Sensitivity of temperature change in oral cavity: The orthodontic force of stainless steel wire and CoCr alloy orthodontic wire is basically not affected by the temperature in oral cavity. The orthodontic force of the superelastic NiTi alloy orthodontic wire varies with the oral temperature. When the amount of deformation is constant. The orthodontic force increased with the increase of temperature. On the one hand, it can accelerate the movement of teeth, because the temperature change in the oral cavity will stimulate the blood flow in the blood stasis area caused by the capillary stagnation of the orthodontic device, so that the repair cells can be fully nourished during the movement of teeth to maintain their vitality and normal function. On the other hand, orthodontists cannot precisely control or measure the orthodontic force in the oral environment. 5. Toxicity resistance: In general, the surface layer of titanium oxidation acts as a barrier, making the Ni-Ti alloy have good biocompatibility. TixOy and TixNiOy in the surface layer can inhibit the release of Ni. 6. Gentle orthodontic force: Currently, commercially available orthodontic wires include austenitic stainless steel wires, cobalt-chromium-nickel alloy wires, nickel-chromium alloy wires, Australian alloy wires and titanium alloy wires. Load-displacement curves for these orthodontic wires under tensile and three-point bending test conditions. Nitinol has the lowest and most flat plateau of the unloading curve, indicating that it provides the most durable and gentle orthodontic force. 7. Good shock absorption characteristics: The greater the vibration of the arch wire caused by chewing and bruxism, the greater the damage to the root and periodontal tissue. Through the study on the attenuation experiment of different archwires, it is found that the vibration amplitude of stainless steel wire is larger than that of superelastic nickel-titanium wire, and the initial vibration amplitude of superelastic nickel-titanium archwire is only half of that of stainless steel wire. The good vibration and shock absorption characteristics of archwires are very important for the health of teeth,nickel titanium wire, while traditional archwires, such as stainless steel wires, tend to aggravate root resorption. Global integrated service provider in the field of shape memory alloy temperature control Return to Sohu to see more Responsible Editor:.


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