等离子渗氮和镀膜复合处理对氟环境中纯钛耐腐蚀性能的影响

目的：观察等离子渗氮和磁控溅射镀膜复合处理对氟环境中纯钛铸件耐腐蚀性能的影响。方法：用动电位极化技术测试对照组和复合处理组纯钛铸件在氟质量浓度为1000mg/L的人工唾液中的自腐蚀电流密度和自腐蚀电位,扫描电镜观察试件表面形貌,能谱分析腐蚀面的微量元素,对结果进行分析比较。结果：对照组和复合处理组纯钛铸件在氟离子1000mg/L的人工唾液中的自腐蚀电流密度分别为（3101.58±245.07）nA和（8.60±0.45）nA,自腐蚀电位分别为（-0.50±0.11）V和（-0.20±0.02）V。复合表面处理后纯钛铸件的自腐蚀电流密度明显减小（P〈0.01）,自腐蚀电位明显大（P〈0.01）。扫描电镜显示,复合处理后纯钛铸件较对照组纯钛铸件的表面腐蚀形貌明显减轻,对照组纯钛铸件腐蚀面发现氟元素而复合处理组未发现氟元素。结论：等离子渗氮和磁控溅射镀膜复合处理能明显提高纯钛铸件的耐腐蚀性。

Effect of Compound Treatment on the Corrosion Resistance of Casted Titanium in Fluoride Environment.

Objective： To study the effect of plasma nitriding and TiN--coated compound treatment on the corro- sion resistance of casted titanium in fluoride environment. Methods： Potentiodynamic polarization technique was use to measured the current density of corrosion （Icorr） and the electric potential of corrosion （Ecorr） of control group and treated group in the artificial saliva with 1000 mg/L fluoride concentration. After electrochemical experiment, the microstructure was observed by scanning electron microscope （SEM） and the element microanalysis was scaned by energy dispersive spectrometry （EDS）. Results： The Icorrs of control group and treated titanium were 3101.58-4- 245.07 and 8. 604-_0.45 nA respectively. The Ecorrs were --0.50--4-_0.11 and --0.20~0.02 V respectively. The Icorrs of treated titanium were significantly lower than control group titanium and the Ecorrs of treated titanium were significantly higher than control group titanium. The surface of titanium control group was corroded more heavily than treated titanium and F element was found in the surface of untreated titanium, but there was not F ele- ment in the surface of treated titanium. Conclusion： The corrosion resistance of titanium were increased significantly after plasma nitriding and TIN--coated compound treatment.