【摘要】 对异型工件盲孔微弧氧化不均匀性进行了研究。结果表明,盲孔内壁膜厚分布很不均匀,由孔口到孔底膜厚逐渐减小,且最大膜厚与最小膜厚相差可达10μm,膜厚降低了85.6%。膜层的不均匀性是由于盲孔内部电场的屏蔽和溶液交换较差协同作用引起的。盲管试件内壁相结构基本相同,只是衍射峰的强弱有所差别,而表面形貌却表现出了很大程度的不均匀现象。为了提高微弧氧化的均匀性,分别采用了在盲孔内部通入循环电解液、引入辅助电极以及两者同时引入的方法进行微弧氧化处理。结果表明在盲孔内部引入辅助电极同时通入循环电解液使得试件内壁膜厚不均匀程度显著减小,与原始处理相比不均匀性减小67%,电流测试也有着同样的变化趋势。更多还原

【Abstract】 The inhomogeneity of the coatings in the blind pipe prepared by Micro-arc oxidation(MAO) coatings were investigated.The results show that the thickness of the coatings is not uniform and decreased gradually from the tube open to bottom.The phase composition hardly changes with only slight difference in diffraction peak intensity,but surface morphology varies substantially.Three experiments were performed to investigate the inhomogeneity effect,i.e.circulation of electrolyte,auxiliary electrode and both of former two.The results demonstrate that the non-uniformity of the coatings is attributed to the shielding effect of electric field and poor circulation of electrolyte.The enhancement of electrolyte circulation and utilization of auxiliary electrode could decrease the inhomogeneity of MAO coatings by 67%.A novel technique to improve homogeneity of MAO coatings has been proposed.更多还原