镁合金蓝色微弧氧化膜的制备及其耐蚀性能

Preparation of Blue Micro-Arc Oxidation Coating on Magnesium Alloy Surface and Evaluation of Its Corrosion Resistance

过去,将微孤氧化着色用于材料装饰的研究较少。采用微弧氧化技术在ZM5镁合金表面制备了蓝色的微弧氧化层,研究了主盐Na2SiO3、着色剂CoSO4浓度和氧化时间对蓝色膜层的影响。结果表明:在70 g/LNa2SiO32,g/L CoSO4,电压440 V,氧化时间20 min条件下,能够获得膜层厚度为82μm的致密蓝色微弧氧化膜层;膜层主要由非晶相组成;氧化膜中Co的氧化物在光的散射作用下导致膜层呈现蓝色;蓝色微弧氧化层能够提高镁合金基体耐腐蚀性能。

Blue oxide coating was prepared on the surface of ZM5 magnesium alloy by micro-arc oxidation. The influences of the concentration of major salt Na2SiO3 and coloring agent CoSO4 as well as oxidation time on the composition and corrosion resistance of as-prepared micro-arc oxidation coating were investigated. It was found that compact blue micro-arc oxidation coating with a thickness of 82μm could be obtained by micro-arc oxidation in the electrolyte consisting of 70 g/L Na2SiO3 and 2 g/L CoSO4 at 440 V for 20 min. Resultant micro-arc oxidation coating, mainly consisting of amorphous phases, appeared blue owing to light scattering of cobalt oxides and was able to effectively improve the corrosion resistance of the Mg alloy substrate.