钛及钛合金多弧离子镀Ta-10W涂层的腐蚀性能

Corrosion performance of Ta-10W coating on titanium and its alloy by multi-arc ion plating

采用多弧离子镀技术在工业纯钛(CP-Ti)及TC4合金基体上制备Ta-10W涂层以改进钛及钛合金在人体及海洋环境中的腐蚀性能。借助扫描电镜(SEM)、X射线衍射(XRD)、动电位极化及电化学阻抗谱(EIS)试验等测试手段对涂层在模拟人体及海洋环境中的耐蚀性能进行研究。结果表明:Ta-10W涂层连续、致密且厚度均匀,主要组成相为体心立方α-Ta;在林格溶液及模拟海水溶液中,涂覆Ta-10W涂层后的腐蚀电位值均较两种基体升高、腐蚀电流密度下降,其中CP-Ti基体上的涂层在林格溶液中的腐蚀电流密度下降至2.648×10^-9A/cm^2,在模拟海水溶液中则下降至2.548×10^-9A/cm^2,较CP-Ti基体的下降一个数量级。Ta-10W涂层对TC4基体也有较好的改善效果;并且Ta-10W涂层使CP-Ti及TC4在两种溶液中的电荷转移电阻增大了1~2个数量级,涂覆涂层使双电层的介电性也有较大提升,有效提高了CP-Ti和TC4在不同溶液环境中的耐腐蚀性能。故Ta-10W涂层对CP-Ti和TC4在人体和海洋环境中的腐蚀具有良好的防护作用,对于钛及钛合金在此环境中的应用具有指导意义。

To improve the corrosion performance of titanium and titanium alloy in human body and Marine environment, the Ta-10W coating was prepared on the commercial pure titanium (CP-Ti) and TC4 matrix by multi-arc ion plating. The corrosion resistance of the coating in simulated human body and Marine environment was studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), electrodynamic polarization and electrochemical impedance spectroscopy (EIS) test. The results show that the Ta-10W coating is continuous, dense with uniform thickness. The mainly phase is body-centered cubic α-Ta. Ta-10W coated samples corrosion potential is higher and corrosion current density is lower in ringer solution and simulated seawater solution. The Ta-10W coating on CP-Ti reduces the corrosion current density to 2.648×10^-9 A/cm^2 in ringer solution and 2.548×10^-9 A/cm^2 in simulated seawater solution, which is an order of magnitude lower than that of CP-Ti matrix, and also has excellent improvements on TC4 matrix. In addition, Ta-10W increases the charge transfer resistance of CP-Ti and TC4 by 1 or 2 orders of magnitude in the two solutions. The dielectric property of the double layer is also improved by coating Ta-10W, thus the corrosion resistance of CP-Ti and TC4 in different solution environments is effectively improved. Therefore, Ta-10W coating has a good protective effect on the corrosion resistance of CP-Ti and TC4 in human body and marine environment, and is instructive for the application of titanium and titanium alloy in these environments.