NiTi alloy has the characteristic of the shape-memory. It will return to its previous shape from the deformation at some specific temperature. It also contains some significant characteristics, such as super-elastic, anti-abrasive, anti-corrosive, high damping, and radiopacity, and generates no effect on MRI. In aerospace engineering applications, it has been used to assemble the space station antenna. It is the material for tooth archwire and coronary stent for medical use. However, the application of NiTi alloy is limited by the characteristic of processing difficulty. Some issues come with the processing, for example, the wastage of cutter when the material is difficult to process, the formation of burr occurs in processing, and surface oxidation happens when welding.
Hence, powder metallurgy is usually used to manufacture NiTi alloy, especially near-net shape parts. Powder metallurgy is frequently used in industry, which includes Conventional Sintering (CS), Self-Propagation High-Temperature Synthesis (SHS), Hot Isostatic Pressing (HIP), Spark Plasma Sintering (SPS), Metal Injection Molding (MIM), and Select Laser Melting (SLM). There is a key factor in how to use NiTi alloy among all these methods: fabricating NiTi alloy powder. Usually, NiTi alloy powder is fabricated by gas atomization. However, there are four problems arose in such a processing way: The pollution of the crucible could cause the composition control problem; The shape memory ability will be affected by the brittle phase coexistence of Ti2Ni, Ti4Ni2Ox and TiNi3 instead of the pure NiTi phase in solidification process; gas atomized powders have small adhering satellites which are the small particles attached big powder during the manufacturing process; Excess oxygen content cause composition changes. To avoid the above bothersome problems, the plasma rotating electrode process (PREP) is one of the excellent procedures for producing NiTi alloy powder10. PREP has been extensively used in material and metallurgy due to no pollution, as well as those generated in gas atomization. The present work aims to link the relationship between process parameters and weight percentages of different sizes and the capability of NiTi powder for biomedical applications. If you are looking for high quality, high purity and cost-effective Nickel Titanium, or if you require the latest price of Nickel Titanium, please feel free to email contact mis-asia.
