The new characteristics of titanium materials have opened up promising new application prospects.

Titanium has excellent biocompatibility and affinity with the human body. It is lightweight, corrosion-resistant, odorless, and non-toxic, making it widely used as a biomaterial. In recent years, the development of porous Ni-Ti shape memory alloys has opened up entirely new application prospects in the medical field. This alloy exhibits precise dynamic functionality, capable of accurately recovering its original shape after undergoing significant plastic deformation and subsequent heating. When fabricated into small stents and implanted into arteries, the expansion effect can be used to open blocked lumens, restoring blood flow. Such stents can also be used for clearing blockages in other human organs, including the esophagus, trachea, bile ducts, and urinary system. Furthermore, superelastic Ti-Ni alloys are used as highly sensitive guide wires in implanted human organs, offering good torsional properties, recoverability, and low oscillation.

Powder metallurgy methods for preparing porous Ni-Ti alloys include the pre-alloyed powder method, self-propagating high-temperature synthesis, hot isostatic pressing, and the elemental powder mixing and sintering method. Among these, the elemental powder mixing and sintering method uses metal powders as raw materials, which are mixed, compacted, and sintered to obtain various products, making it an important method for preparing porous Ni-Ti shape memory alloys. The alloy prepared by pressing at 140 MPa and solid-state sintering at 950°C features NiTi as the main phase, with suitable porosity, offering high porosity, excellent mechanical properties, shape memory performance, and biocompatibility.