NiTi合金表面改性研究进展

Progress in Surface Modification of NiTi Shape Memory Alloy

近等原子比NiTi形状记忆合金具有优异的形状记忆效应、超弹性以及良好的耐腐蚀性。NiTi合金制备的多种生物医学植入体已经实现了临床应用。但是,NiTi合金在体液的长期腐蚀下析出的Ni离子,可能对人体造成过敏、发炎和致癌等风险。介绍了近几年来采用氧化、等离子体和涂层方法对NiTi形状记忆合金进行表面改性的研究进展情况,这些表面处理主要是对NiTi合金表面自然形成的氧化层进行改造,形成更加稳定、耐腐蚀性能更高的新表层,以抑制或者隔绝Ni离子的溶出,从而提高合金在长期使用情况下的生物相容性。分别对这几种改性方法的优缺点进行了总结,最后指出了表面改性研究的未来发展方向。

The near-equiatomic NiTi shape memory alloy was a functional material with unique shape memory effect, superelasticity and good corrosion resistance. However, Ni ＋ released from NiTi during the long-term corrosion in human body liquids can cause the risks of allergy, inflammatory and cancerogenic reactions. The research progresses on surface modification of NiTi shape memory alloy by oxidation, plasma and coatings in recent years were reviewed. The aim of the modification was to modify the naturally generated ox- ide on the surface of NiTi alloy and form a new stable surface with enhancing corrosion resistance, suppressing the release of Ni ＋ and thus improving the long-term biocompatibility. The advantages and disadvantages of these surface modification methods were summa- rized. Finally, the main research directions in the future of surface modification on NiTi were proposed.