镁合金微弧氧化黑色膜的制备工艺和结构

Preparation process and microstructure of black coatings on magnesium alloy by micro-arc oxidation

用微弧氧化的方法,通过两种电解液体系在AZ91D镁合金基体上获得颜色均匀、致密性好的黑色陶瓷层,研究了在这两种体系中,着色盐成分、浓度,以及氧化电压和处理时间对氧化陶瓷层的影响。结果表明:试样在两种电解液体系中皆能得到黑色陶瓷层,不同的基础电解液所需加的着色盐不同,在硅酸盐体系中以CuSO4为主要着色盐,在磷酸盐体系中以CoSO4为主要着色盐。着色盐浓度和氧化电压对膜层颜色影响较大,在一定范围内,随着氧化电压的上升,膜层颜色有所加深,而相同条件下氧化时间的改变对颜色变化影响较为缓和。通过比较,发现在磷酸盐体系中膜层表面质量最好。

Uniform and dense black oxide ceramic coatings were prepared on AZ91D magnesium alloy by micro-arc oxidation two kinds of electrolyte systems.Effects of electrolyte components,oxidation voltage in time on the black coatings were studied.Results show that the black ceramic layer can be obtained in both two kinds of electrolyte system with different coloring salt by micro-arc oxidation（MAO）,in sodium silicate solution with complex of copper sulfate and ammonia and in sodium dihydro phosphate with cobaltous sulfate.The electrolyte concentration and oxidation voltage are the most important factor which influences in the color of coatings.In a certain range,with the increase of oxidation voltage black of the coatings is deepened,while no significant effect of treatment time on the color of the coatings is observed under the same electrolyte concentration.The coatings prepared in silicate electrolyte system show the best surface appearance.