阳极氧化铝膜抗电强度的研究

Dielectric strength of anodized aluminum oxide film

实验研究电解液温度、草酸浓度、草酸-硫酸混酸浓度、电流密度及膜层厚度等因素对阳极氧化铝膜的抗电强度的影响.结果表明,随生长条件不同,阳极氧化铝膜的抗电强度在50~120 V/μm范围内变化.其中,电解液温度对抗电强度影响大,降低电解液温度有利于抗电强度的提高;电流密度对抗电强度的影响存在最佳值特征,低于该值时,氧化终止电压低,随之膜层抗电强度低,高于该值时,氧化电压随电流密度非线性上升,热功耗过大导致实际氧化温度上升,抗电强度降低;草酸电解液制备膜层的抗电强度高,并随草酸浓度上升而提高,微量硫酸添加均会导致抗电强度的下降;抗电强度随膜层厚度增加呈现先上升后下降的特征.

The influences of anodizing parameters on the dielectric strength（DS）of AAO film wereinvestigated,including the temperature of electrolyte,the concentration of oxalic acid,the concentration ofmixed oxalic acid and sulfuric acid,the density of anodizing current and the thickness of the AAO film. Theresults show that the DS of AAO varies between 50 120 V/μm depending on the anodizing parameters. Theoxidized temperature had dramatic influence on DS. The lower the temperature of electrolyte is,the higher theDS is.There is an optimum current density,if lower than the current density,the ending voltage is low,therewith a low DS;if higher,the voltage increases nonlinearly,and thereafter the thermal dissipation resultsin a low DS. Oxalic acid as electrolyte can give a high DS,trace sulfuric acid addition results in DSdecreasing quickly. As the thickness of AAO increase,the DS will increase first and then decrease.