多孔NiTi合金直流-脉冲阳极氧化表面改性研究

Study on Surface Modification of Porous NiTi Alloys by Direct

摘要:

采用低温直流-脉冲阳极氧化技术对多孔NiTi合金表面进行改性，分析直流-脉冲阳极氧化过程，利用XPS、SEM、动电位极化对阳极氧化膜的组成、形貌以及耐腐蚀性进行研究，观察阳极氧化前后多孔NiTi合金在模拟人工体液中Ni离子释放行为。研究结果表明在直流3 A、脉冲6 A下阳极氧化的多孔NiTi合金表面形成了一层均匀的多孔氧化膜，其厚度在190 nm左右，主要成分为Ti的氧化物，阳极氧化后多孔NiTi合金的耐腐蚀性显著提高，其Ni离子释放速率大幅度降低。

Abstract:

Surface of porous NiTi alloys was modified by direct current-pulse anodic oxidation technology at low temperature. The process of direct current-pulse anodic oxidation was analyzed. The phase composition, morphology and anti-corrosion behavior of the anodic oxidation film were studied by XPS, SEM and potentiodynamic polarization, respectively. The Ni release of porous NiTi alloys before and after anodic oxidation was investigated in simulated body fluid. The results show a uniform porous oxidation film with a thickness of about 190 nm on the surface of the porous NiTi alloy was obtained after anodic oxidation at direct current of 3 A and pulse current of 6 A. The oxidation film was mainly composed of the oxides of Ti. The corrosion resistance of porous NiTi alloys was obviously improved and the rate of Ni release was significantly reduced after anodic oxidation.