阳极氧化表面处理对纯钛腐蚀性能的影响

目的：模拟口腔环境,研究阳极氧化纯钛试样在不同氟离子浓度人工唾液中的腐蚀情况。方法：采用塔菲尔（tafel）曲线测试,测定阳极氧化纯钛试样及自然氧化纯钛试样在不同氟离子（F^-）浓度（500×10^-6、750×10^-6、1000×10^-6）人工唾液中的自腐蚀电流密度（Icorr）、极化电阻（Rp）,并以人工唾液为对照组进行比较分析。场发射扫描电镜（FSEM）观察不同纯钛试样腐蚀前后形貌。结果：F^-和阳极氧化对纯钛腐蚀性的影响均有显著性,P〈0.05。1.纯钛试样在含氟人工唾液中Icorr明显增大,Rp明显减小,腐蚀速度加快。2.对纯钛试样进行阳极氧化后,在四种腐蚀介质中Icorr均明显减小,Rp明显增大,腐蚀速度减慢。3.纯钛试样在F-浓度为500×10^-6人工唾液中Icorr最大,Rp最小,腐蚀速度最快。结论：人工唾液中加入F-后纯钛试样的腐蚀加重,且在F-浓度为500×10^-6时纯钛试样腐蚀最严重;阳极氧化可以显著提高纯钛试样的耐腐蚀性。

Effect of Anodic Oxidation on the Corrosion Resistance of Pure Titanium

Objective： To study the corrosion resistance of anodic oxidized pure titanium in the artificial saliva with. Methods： Tafel measurement was used to measure the electric potential of corrosion（ Ecorr）, current density of corrosion （Icorr） and polarization resistance（Rp） of anodic oxidized and natural oxidieed pure titanium in artificial saliva which included different fluoride concentrations（500 ppm. 750 ppm. 1000 ppm）. After electrochemical analysis, microstructural and phase diffraction was examined by field - emission scanning electron microscopy （FSEM）. Results： Fluoride and anodic oxidation can significantly affect the corrosion resistance of titanium（P 〈0.05 ）. Firstly, the Icorr of pure titanium increased obviously in artificial saliva containing fluorine, the Rp reduced and corrosion rate increased. Secondly, after anodic oxidation, Icorr of pure titanium in four kinds of corrosion medium all reduced obviously, Rp increased and the corrosion speed dropt. Finally, when the fluoride concentration was 500 ppm, the Icorr of pure titanium was the largest, the Rp was the smallest and corrosion rate was the fastest. Conclusion： Pure titanium was corroded more seriously in the artificial saliva added with Fluoride. When fluoride concentration was 500 ppm, the corrosion of titanium was most obviously. However, anodic oxidation could obviously increase the corrosion resistance of the pure titanium.