In the medical field,nitinol is used in interventional radiology,plastic surgery,neurology and cardiology. The most representative is nitinol stent. Compared with the traditional 316L stainless copper stent,nitinol stent performs well in terms of antithrombotic,anti-corrosion and low elastic modulus, so nitinol instead of 316L stainless steel can effectively improve medical effects.
Biomedical nitinol alloy stent includes wire braided stent and tube cutting stent, wherein the blank of the cutting stent is nitinol alloy tube,and other medical devices also use nitinol alloy tube, such as catheters and probes.
In the field of aviation,nitinol alloy tubes can be used as connectors for the hydraulic systems of satellites and fighter aircraft,which can make operation more stable and safe.
Plastic deformation is the main means of processing nitinol alloy tubes.The main process is extrusion and drawing.
The extrusion process includes anti-extrusion,positive extrusion and deformable core mold extrusion.Compared with the extrusion process,the nitinol alloy pipe prepared by the drawing process can reach the biomedical grade.
Drawing process is divided into four kinds according to whether there is a core mold:core mold drawing,no core mold drawing,floating core drawing and fixed core drawing. If the drawn core mold plastic deformation occurs,the core mold drawing is also known as deformable core mold drawing,on the contrary, the core mold drawing does not occur plastic deformation is also known as non-deformable core mold drawing.
The nitinol tube implanted in the human body not only has to withstand millions of cyclic loads,but there may be emergencies that make the nitinol alloy tube crack or even completely break. In other fields,the nickel-titanium alloy tube also needs to have higher mechanical properties,so it is of great practical significance to improve the mechanical properties of the nitinol alloy tube.