表面不同形貌对钛耐腐蚀性能影响的实验研究

Corrosion resistance research on pure titanium with different roughness of the surface

目的:评价不同方法表面处理后纯钛表面粗糙程度对其耐腐蚀性能的影响。方法:制备33个纯钛试件并随机分为3组,分别进行喷砂、阳极氧化和机械抛光处理,应用扫描电镜观察不同处理后钛件表面微形貌,在酸性含氟人工唾液中测试开路电位和阳极极化曲线。结果:扫描电镜结果显示喷砂后钛表面有大量的弹坑和划痕,深度较深,且形状不规则,大小不一,边缘锐利,为微米级粗糙表面形态;而阳极氧化表面为大小均一的直径80 nm的纳米管状结构,为纳米级粗糙表面形态;机械抛光表面划痕明显,深度较浅,为微米级粗糙表面形态。在酸性含氟人工唾液中,3组之间自腐蚀电位值的比较为:阳极氧化组>机械抛光组>喷砂组;腐蚀电流密度值的比较为:喷砂组>机械抛光组>阳极氧化组,具有显著性差异(P<0.05)。结论:不同的表面处理技术改变了钛材料表面的微形貌并影响了钛的耐腐蚀性能,经阳极氧化处理后的纳米级表面具有更好的耐腐蚀性能,喷砂会使钛的耐腐蚀性降低。

Objective： To evaluate the corrosion resistance of different roughness surface of the titanium after different surface treat- ment. Methods： Thirty-three pure titanium specimens were cast and divided into three groups randomly, and then were treated by sandblasting, anodic oxidation and mechanical polishing separately. SEM was thereafter used to observed the surface of titanium after modification. Open circle potential and anode polarization curve were determined in acid artificial saliva containing fluoride. Results： SEM results showed that the surface of titanium after sandblasting exhibited micro-topographical massive deep scratches and pits of ir- regular shape, different size and sharp edge. But on the anodic oxidation surface nanotopographic, 80 nm-diameter nanotubes were formed. The surface of titanium after mechanical polishing had micro-topographic shallow scratches. In the acid artificial saliva, the cor- rosion potentials of three groups were in the sequence of anodic oxidation group 〉 mechanical polished group 〉 sandblasted group. The corrosion currents of three groups were sandblasted group 〉 mechanical polished group 〉 anodic oxidation group. Both data have statisti- cal significance. Conclusions： Different surface modifications changed the topography of the titanium and affected the titanium＇s corro- sion resistance. The nanotopograhpy of titanium achieved by anodic oxidation had better corrosion resistance and sandblasting reduced the corrosion resistance of titanium.