Mg-Gd-Y-Zr合金表面铈转化膜制备及耐蚀性能

Formation and Corrosion Resistance of Cerium Conversion Film on Mg-Gd-Y-Zr Alloy

摘要:

采用容量法研究了Mg-Gd-Y-Zr合金表面铈转化膜的耐蚀性能，通过正交试验获得在其表面制备铈转化膜的最佳条件：pH值为10.0，成膜时间为30 min，成膜促进剂的浓度为0.05 mol/L，成膜温度为25 ℃。其影响程度为pH值>成膜时间>成膜促进剂的浓度>成膜温度。比较了铈转化膜、铬酸盐转化膜及光板镁合金在3.5%NaCl溶液中的耐蚀行为。实验结果表明铈转化膜显著地提高了镁合金的耐腐蚀性能。

Abstract:

Corrosion resistance of cerium conversion film on Mg-Gd-Y-Zr alloy was investigated by volumetric method. The optimum deposition parameters were obtained by orthogonal table L9(43), i.e. pH value 10.0, electrochemical deposition time 30 min, accelerating agent concentration 0.05 mol/L, and temperature 25 ℃. The influence degrees on corrosion resistance were in the sequence of pH > electrochemical deposition time > accelerating agent concentration > temperature. The corrosion resistance of cerium conversion film, chromated conversion film and Mg-Gd-Y-Zr magnesium alloy in 3.5% NaCl solution was compared by measuring the rate of evolved hydrogen. Results show that cerium conversion film improves the corrosion resistance of RE-Mg alloys remarkably.