Micro Electrochemical Polishing of TiNi Alloy for Medical Stent

The medical stent is using widely for a surgical operation, because it can reduce the pain of cardiac. When it was developed initially, medical stent was made of stainless steel, however, the TiNi alloy is widely using presently instead of stainless steel. Because, TiNi alloy has not only super elasticity and Smart Material Effect (SME) but also excellent organism compatibility. For these reason, the TiNi alloy is currently highlighted for medical stent material better than other materials. Nevertheless, this TiNi alloy is not suitable to traditional machining process. When the traditional machining process is conducted to the TiNi alloy, it cannot be discharged the machining heat and inner stress. Also, traditional machining process makes a lot of microscopic burrs on the TiNi alloy surface. This microscopic burrs and the rough surface makes injury on vascular, so, it should be necessary non-traditional machining process without defect of traditional machining. In this paper, microscopic burrs on TiNi alloy for medical stent are removed, and surface roughness of the medical stent is evaluated by Electrochemical Polishing (EP) which is one of the non-traditional machining.