[Biocompatibility evaluation of Ti50Ni50-xCux shape memory alloys (I)--corrosion resistance]
1Lab. of Metallic Biomaterials, Dept. of MSE, Zhejiang University, Hangzhou 310027.
Abstract:
By means of electrochemical methods, the corrosion resistance of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2, 4,6,8) was investigated. It is discovered that repassivation potential of Ti50Ni50-xCux (x = 2,4,6,8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. This means that the added Cu raises the repassivation of TiNi shape memory alloys and improves corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2,4,6,8) alloys increase with the rising solution pH value, but the repassivation potentials keep constant. The added Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1,2,4,6,8) alloys are irrelevant to its Cu content and the values are almost the same as that of TiNi alloys.