氟离子及阳极氧化对纯钛耐腐蚀性的影响

The effect of fluoride and anodic oxidation on the corrosion resistence of pure titanium

目的:模拟口腔环境,研究氟离子(F-)及阳极氧化对纯钛耐腐蚀性的影响。方法:采用塔菲尔(tafel)曲线测试,测定自然氧化纯钛试样及阳极氧化纯钛试样在不同氟离子浓度(500 mg/L、750 mg/L、1 000 mg/L)人工唾液中的自腐蚀电流(Icorr)、自腐蚀电位(Ecorr),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-和阳极氧化对纯钛的腐蚀性均有显著影响(P<0.05)。纯钛试样在含氟人工唾液中Icorr明显增大,腐蚀速度加快。对纯钛试样进行阳极氧化表面处理后,在4种腐蚀介质中Icorr均明显减小,腐蚀速度减慢。纯钛试样在F-浓度为500mg/L人工唾液中Icorr最大,腐蚀速度最快。结论:人工唾液中加入F-后纯钛腐蚀加重,阳极氧化可提高纯钛的耐腐蚀性。

Objective：To study the effect of fluoride concentration and anodic oxidation on the corrosion resistance of pure titanium in the simulated oral environment.Methods：48 pure titanium samples were prepared,24 of them were treated by anodic oxidation.Then the samples were kept in artificial saliva（control）,artificial saliva with fluoride at 500 mg/L,750 mg/L and 1 000 mg/L,respectively（n=6） for 24 h.Tafel measurement was used to measure the electric potential of corrosion（Ecorr） and current density of corrosion（Icorr）,microstructure was examined by field-emission scanning electron microscopy（FSEM）.Results：Fluoride and anodic oxidation significantly affected the corrosion resistance of the samples（P0.05）.After treatment in artificial saliva containing fluorine Icorr of pure titanium increased and corrosion rate increased.After anodic oxidative surface treatment,Icorr of pure titanium in all groups reduced,the corrosion speed decreased.When the fluoride concentration was 500 mg/L,the Icorr of pure titanium was the largest,corrosion rate was the fastest.Conclusion：Fluoride can accelerate the corrosion of pure titanium.Anodic oxidation can increase the corrosion resistance of pure titanium.