Nickel-titanium Alloy Powder Used As A Shape Memory Alloy
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Update time : 2023-04-28 09:11:37
Shape memory materials are widely used in aerospace, automotive, mechanical and electronic, construction, biomedical and other fields due to their unique shape memory effect and super elasticity, as well as their superior properties such as wear resistance, corrosion resistance, high damping, high work-to-weight ratio and biocompatibility. Among these, NiTi-based shape memory alloys are the most important ones because of their fatigue resistance, cyclic stability at low stress levels and excellent biocompatibility, making them the most widely used as medical sensors, dampers, clamps and implants, actuators, etc.
NiTi alloy is the most widely used shape memory alloy and has attracted much attention due to its stable superelasticity and shape memory properties. In recent years, NiTi alloys have been widely used in biologic implant materials due to their superelasticity, shape memory properties and good biocompatibility and corrosion resistance.
Features of NiTi Alloy Powder
The unique mechanical properties of NiTi alloys result from their two phase structures, the B19' martensitic phase with monoclinic structure embodying shape memory, and the B2 austenitic phase with cubic structure having superelasticity, while the austenitic phase can transform with martensite under the influence of temperature, and the content of these two phases present at room temperature depends on the phase transformation temperature, i.e. the start and end of austenitisation (AS and Af) and the beginning and end of martensitisation (Ms and Mf). Below the Af temperature, a rhombic structure of the R-phase transition phase may appear as the B2 phase transforms to the B19' phase. the B2→R-phase transition occurs near precipitates or dislocations and continues to transform to the B19' phase under stress, but the R-phase itself does not have mechanical properties. The shape memory effect of NiTi alloys is due to the stress-induced martensitic phase transformation of the B2 phase under the action of external forces. When the temperature rises above Af the B19' phase transforms back into B2 phase, returning the NiTi alloy to its original shape. Superelasticity is the ability to apply ultra-high external forces to NiTi alloys without plastic deformation above Af temperature.
Preparation Methods of NiTi Alloy Powder
The main methods of preparing shape memory alloys/polymers are melting, powder metallurgy, jet deposition process, 4D printing technology, etc., and then configure the subsequent forging, hot extrusion, rolling, drawing, cold working and other forming processes according to the application requirements. Among them, the melting method is the traditional metal metallurgy process, under the vacuum of the metal raw materials through the electron beam, electric arc, plasma, high-frequency induction heating and then melting, easy to produce impurity pollution, uneven composition, energy consumption, and other problems, and need to be cut and processed to form alloy products. The powder metallurgy method, on the other hand, uses metal or alloy powder for hot isostatic pressing and sintering to prepare the final shape of the alloy product.
Although NiTi alloy has excellent overall performance, the high ductility and strong work hardening during cutting process lead to difficult machining and poor workpiece quality. In response to this problem, many scholars have used laser additive manufacturing as a representative of metal additive manufacturing technology to prepare NiTi shape memory alloys with complex structures to ensure high precision while also giving full play to the properties of the alloy. In order to meet the needs of additive manufacturing, TRUNNANO has developed a spherical NiTi alloy powder suitable for SLM-selective laser melting by designing and blending the composition of NiTi alloy. The NiTi alloy powder has a stable composition, low oxygen content, high sphericity and good flowability to maximise the potential of the NiTi alloy.
NiTi Alloy Powder Supplier
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) is a trusted NiTi alloy powder manufacturer and nitinol powder supplier with over 12-year-experience. We ship our goods all over the world.
If you are looking for high-quality NiTi alloy powder, please feel free to contact us and send an inquiry. ([email protected])
