医用多孔NiTi合金表面微弧氧化改性研究

摘要

In this paper, the biomedical porous NiTi alloys were modified by micro⁃arc oxidation method, and the effect of micro⁃arc oxidation treatment on the microstructure and corrosion resistance of the porous NiTi alloys were also studied. The results showed that the pore structure and the porosity of the porous NiTi alloy was not changed after micro⁃arc oxidation treatment. The typical micro⁃arc oxidation porous coating was formed both on the outside surface and inside surface of the porous NiTi alloy. This coating was mainly composed of alumina phase with a little Ti and Ni element, while the contents of Ti and Ni on the outside coating were lower than those of inside coating. The surface contact angle of the porous NiTi alloys were increased due to the micro⁃arc coating, which made the original hydrophilic surface transform into hydrophobic surface. Moreover, the corrosion resistance of coated porous NiTi alloys were enhanced by more than one order of magnitude compared to the uncoated porous NiTi alloy, and the release number of Ni+was decreased by more than one order of magnitude.%为解决多孔NiTi合金耐蚀性降低和Ni离子释放量增大而引起的使用安全性问题。本文采用微弧氧化技术对医用多孔NiTi合金进行表面改性处理，研究结果表明，微弧氧化处理并未改变多孔NiTi合金原有的孔隙结构和孔隙率，只在其外表面和孔隙内表面均形成了典型的微弧氧化多孔涂层。该涂层主要由氧化铝相组成，并含有少量的Ti和Ni元素，且外表面涂层的Ti和Ni含量要略低于孔隙内表面涂层。微弧氧化涂层提高了多孔NiTi合金的表面接触角，将原有的亲水表面转变成了疏水表面。经微弧处理后，多孔NiTi合金的耐蚀性较基体提高了1个数量级以上，Ni离子释放量也较基体降低了1个数量级以上。