不同电解液浓度下镁合金微弧氧化的比较研究

Influence of Electrolytes Concentration on Film Forming Properties in Micro-arc Oxidation of Magnesium Alloy

为了适应镁合金微弧氧化工艺的工业化应用要求,针对AZ91D镁合金在硅酸盐系电解液环境下,用单位表面积生长单位膜层厚度的电能消耗(kW.h/μm.m2)作为参考指标,研究了不同电解液浓度对成膜速率、膜层表面形貌和耐蚀性及电能消耗的影响。利用自制的具有多种输出脉冲形式的电源,在带放电回路的输出模式下,开展镁合金微弧氧化试验。结果表明,随电解液浓度的升高,起弧电压降低,膜层的成膜速率变大,厚度增大,单位膜层的能耗降低,但膜层的粗糙度增加,孔径及孔隙率增大,耐蚀性变差。综合考虑各方面的因素得出,2倍标准电解液浓度下生成的膜层最优。

In order to make micro-arc oxidation process of magnesium more applicable in the industry, the influence of different electrolytes concentration on the property of the film forming in micro-arc oxidation of magnesium Alloy （ AZ91D alloy in silicate system electrolyte environment） was investigated. Taking growthing unit membrane layer thickness of the electrical energy consumption on unit surface area as the reference index, the impacts of different electrolyte concentration on the forming efficiency of the film, its surface topography, the corrosion resistance and the power consumption were studied. It takes the advantages of power supply with multiple output power pulses designed by ourselves to conduct the micro-arc oxidation experiment in the output mode of discharge loop. The results show that, with the increase of electrolyte concentration, the arcing voltage and the power consumption of forming film decreases gradually and the film-forming rate and the thickness of the film increases. But the roughness of the film, the aperture and the porosity increases, and corrosion resistance decreases. It concludes that micro-arc anodized films with high quality can only form in the electrolyte with 2 times concentration.