Introduction to Nitinol Powder

Overview of Nitinol Powder

Nitinol is a binary alloy composed of nickel and titanium and is a shape memory alloy. Shape memory alloy is a special alloy that can automatically restore its plastic deformation to its original shape at a certain temperature. Its expansion rate exceeds 20%. The fatigue life is 1*10^7. Damping characteristics are 10 times that of ordinary springs. Its corrosion resistance is better than the best medical stainless steel, so it can meet the needs of various engineering and medical applications, and it is a very good functional material.

In addition to the unique shape memory function, memory alloys also have excellent properties such as wear resistance, corrosion resistance, high damping, and superelasticity.

Nitinol alloys have two distinct crystal structure phases, austenite and martensite, due to changes in temperature and mechanical stress. The phase transformation sequence of Nitinol during cooling is parent phase (austenite phase)-R phase-martensite phase. The R-phase is rhombohedral, with austenite at higher temperatures (greater than the same: the temperature at which austenite started), or when the load is removed, cubic, hardened. The shape is relatively stable. While the martensite phase is in a relatively low temperature (below Mf: the end temperature of martensite) or loaded (by external activation), it is hexagonal, ductile, repeatable, unstable, and easily deformable.

Physicochemical Properties of Nitinol Powder

1) Shape memory. 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 below Mf and heated to below Af. Through the reverse phase transition, the material will automatically return to the shape of its parent phase. In fact, the shape memory effect is a thermally induced phase transition of nitinol.

2) Super elastic. The so-called superelasticity refers to the phenomenon that the strain of the sample is much larger than its elastic limit under the action of external force, and the strain energy recovers automatically during the unloading process. That is, in the parent state, due to the action of external stress, stress-induced martensitic transformation occurs, and the alloy exhibits mechanical behavior different from ordinary materials. Its elastic limit is much larger than that of ordinary materials, and it no longer obeys Hooke's law. In contrast to shape memory properties, superelasticity does not involve heat. In short, hyperelasticity means that within a certain deformation range, the stress does not increase with the increase of the strain. Hyperelasticity can be divided into linear hyperelasticity and nonlinear hyperelasticity. In the previous stress-strain curve, the relationship between stress and strain is almost linear. Nonlinear superelasticity refers to the result of stress-induced martensitic transformation and its inverse transformation during loading and unloading within a certain temperature range above Af, so nonlinear superelasticity is also called transformation pseudoelasticity. The pseudoelasticity of Nitinol is about 8%. The superelasticity of nitinol alloys can be changed with changes in heat treatment conditions. When the wire is heated to 400°C or above, the superelasticity begins to decrease. Nonlinear superelasticity refers to the result of stress-induced martensitic transformation and its inverse transformation during loading and unloading within a certain temperature range above Af, so nonlinear superelasticity is also called transformation pseudoelasticity. The pseudoelasticity of Nitinol is about 8%. The superelasticity of nitinol alloys can be changed with changes in heat treatment conditions. When the wire is heated to 400°C or above, the superelasticity begins to decrease. Nonlinear superelasticity refers to the result of stress-induced martensitic transformation and its inverse transformation during loading and unloading within a certain temperature range above Af, so nonlinear superelasticity is also called transformation pseudoelasticity. The pseudoelasticity of Nitinol is about 8%. The superelasticity of nitinol alloys can be changed with changes in heat treatment conditions. When the wire is heated to 400°C or above, the superelasticity begins to decrease.

3) Sensitivity to oral temperature. The orthopedic force of stainless steel wire and CoCr alloy dental orthodontic wire is basically not affected by oral temperature. The orthodontic force of superelastic Nitinol orthodontic wire varies with oral temperature. when the deformation is constant. Orthodontic force increases with increasing temperature. On the one hand, it can accelerate the movement of the teeth, because the temperature change in the mouth stimulates the blood flow in the area of blood stagnation caused by the capillary stagnation caused by the appliance, so that the cells in the repair process are repaired. Tooth movement can be well nourished and maintain its vitality and normal function. Orthodontists, on the other hand, cannot accurately control or measure corrective forces in the oral environment.

4) Corrosion resistance. Studies have shown that the corrosion resistance of nickel-titanium wire is similar to that of stainless steel wire.

5) Anti-toxicity: Nitinol shape memory alloy contains about 50% nickel, which is known to have carcinogenic and cancer-promoting effects. In general, the oxidation of the surface titanium acts as a barrier, giving Ni-Ti alloys good biocompatibility. The surface TiXOy and TixNiOy can inhibit the release of Ni.

6) Soft orthodontic force. Commercially used orthodontic wires include austenitic stainless steel wire, cobalt-chromium-nickel alloy wire, nickel-chromium alloy wire, Australian alloy wire, gold alloy wire and ß-titanium alloy wire. Load-displacement curves of these orthodontic wires under tensile test and three-point bending test conditions. Nitinol has the lowest and flattest platform of the unloading curve, indicating that Nitinol can provide the longest and smoothest corrective force.

7) Good shock absorption. The greater the vibration caused by chewing and night grinding on the arch wire, the greater the damage to the root and periodontal tissue. Through different attenuation experiment results, it is found that the vibration amplitude of the stainless steel arch wire is larger than that of the superelastic nickel titanium wire, and the initial vibration amplitude of the super elastic nickel titanium arch wire is only half of that of the stainless steel wire, and the arch wire has good vibration damping and shock absorption characteristics. The quality of the teeth is important to the health of the teeth, and traditional arch wires such as stainless steel wires tend to increase root resorption.

Applications of Nitinol Powder

Nitinol powder can meet the needs of various engineering and medical applications and is an excellent functional material. In addition to its unique shape memory function, memory alloys also have excellent functions such as wear resistance, corrosion resistance, high damping and superelasticity.

The tensile strength of Nitinol can reach 1000 MPa, which means that it takes more than 100 grams per square millimeter to break it. This force is stronger than ordinary steel, and it also has good "memory" properties and corrosion resistance.

Nitinol is 50% nickel and 50% titanium, which means 50% nickel and 50% titanium. The temperature range of the shape memory can be adjusted by the control element. Generally, the higher the nickel content of Nitinol, the lower the working temperature. When it contains 55% nickel and 45% titanium, the memory alloy can work at room temperature.

People take advantage of this property of shape memory alloys to make pearl necklaces and bracelets made of shape memory alloy wires, as well as bras woven from shape memory alloy wires. Wearing these decorations and health products on the body will restore the original curvature and rigid body temperature under the action, thus playing the role of decoration and health care. In addition, you can use Nitinol to make orthodontic wires to straighten deformed teeth according to human oral temperature.

Nitinol can be used to replace traditional actuators (solenoid valves, servo motors, etc.), such as the simple hexapod robot Stiquito.

Nitinol springs are used in fluid thermal valves, where the material acts as both a temperature sensor and an actuator.

The alloy is used as autofocus actuators in action cameras and optical image stabilizers in mobile phones.

Alloys are used in pneumatic valves for a comfortable seat, which has become the industry standard.

The alloy Chevrolet Corvette contains a Nitinol actuator that replaces the heavier electronic transmission to open and close the hatch to release air in the torso, making it more accessible.

Nitinol powder price

The price of nickel-titanium alloy powder will change randomly with production cost, transportation cost, international situation, exchange rate and supply and demand of nickel-titanium alloy powder market. Tanki New Materials Co., Ltd. aims to help various industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full range of customized services. If you are looking for Nitinol powder, please feel free to send an inquiry to get the latest Nitinol powder price.

Supplier of Nitinol Powder

As a global supplier of Nitinol powders, Tanki New Materials Co., Ltd. has extensive experience in the performance, application and cost-effective manufacturing of advanced engineering materials. The company has successfully developed a series of powder materials (including water-based stearic acid emulsion, water-based calcium stearate, zinc stearate, etc.), high-purity targets, functional ceramics and structural devices, and provides OEM services.