材料期刊网

目的：采用电化学阳极氧化法，在SP700钛合金的表面制备多孔结构的氧化膜。方法利用AutolabPGSTAT30型电化学工作站，采用三电极体系，辅助阴极为石墨电极，参比电极为饱和甘汞电极，工作电极为试样，测定试样的动态极化曲线和阳极氧化I-t曲线。利用扫描电子显微镜观察阳极氧化表面多孔氧化膜的微观形貌，分析热处理工艺、阳极氧化电压、电解液成分等参数对SP700钛合金阳极氧化行为的影响规律。结果钛合金材料经固溶时效处理后，α相和β相的相对含量发生了变化，从而使氧离子对电化学反应界面的内应力发生变化，使得表层氧化膜更加平整，耐腐蚀性提高。 F-是阳极氧化膜上纳米孔形成的必要条件，随着F-浓度的增加，阳极氧化膜表面纳米孔的密集程度增加，孔径减小，氧化膜厚度增加。在一定范围内，随着阳极氧化电压的增大，氧化膜增厚，但电压过高会破坏氧化膜的稳定性。结论用电化学阳极氧化法处理钛合金表面，得到了多孔结构的氧化膜，获得了理想的耐腐蚀性能。固溶时效处理后，钛合金的耐腐蚀性提高。

ABSTRACT:Objective To fabricate nanoporous film on SP700 titanium alloy by electrochemical anodic oxidation. Methods The dynamic polarization curves and I-t curves were conducted using AutolabPGSTAT30 electrochemical workstation, which adopted three-electrode system, for instance, graphite as auxiliary electrode, SCE as reference electrode, and sample as working electrode. The micro-morphology of porous films on the matrix was observed by SEM. Meanwhile, the effects of process parameters such as heat treatments, anodic oxidation voltage and composites of electrolytes on anodic oxidation behavior were investigated. Results The relative content of α and βphase of titanium alloy changed after solid solution-aging treatment, which made oxygen ion reacted ac-cording to the inner stress on electrochemical reaction interface. Thus, smoother films and excellent corrosion resistance were ob-tained. The F- was a necessary condition of the formation of nanoporous films. The intensity of nanoporous and the thickness of films increased with the increase of F- concentration, what′s more, the diameter of porous decreased as the F- concentration in-creased. The thickness of oxide films increased with the increase of anodic oxidation voltage in certain range. However, excessively high voltage would damage the stability of the oxide films. Conclusion Porous films could be formed on the matrix of titanium alloy by electrochemical anodic oxidation, and gained ideal corrosion resistance. The corrosion resistance of titanium alloy increased un-der conditions of solid solution-aging treatment.