电参数及电解液浓度对镁合金微弧氧化膜层性能的影响及应用  

The Effect and Application of Electrical Parameters and Electrolyte Concentration on the Properties of Micro-Arc Oxidation Coating on Magnesium Alloy

作　　者：毕勇 王鹏越 孙伟[1] 王成刚 王天华 邱鑫[1] Bi Yong;Wang Pengyue;Sun Wei;Wang Chenggang;Wang Tianhua;Qiu Xin(Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;FAW Foundry Co.,Ltd.,Changchun 130011)

机构地区：[1]中国科学院长春应用化学研究所,长春130022 [2]一汽铸造有限公司,长春130011

出　　处：《汽车工艺与材料》2025年第4期25-34,共10页Automobile Technology & Material

基　　金：吉林省、长春市重大科技专项(20220301026GX);国家自然科学基金(U21A20323,U23A20128);中国科学院青年创新促进会(2023234);吉林省科技发展计划项目(SKL202302038);河北省科技重大专项(23291001Z)及邗江区科技计划项目。

摘　　要：为研究电参数和电解液浓度对镁合金微弧氧化膜层性能的影响,以Mg-Zn系镁合金为研究载体,采用硅酸盐体系电解液,在镁合金表面制备了微弧氧化膜,通过改变电参数及电解液浓度,研究了不同参数对微弧氧化膜层性能的影响。结果表明:随着电压的升高、占空比的增加、频率的减小,提供的能量增加,膜层生长速率加快,膜层厚度随之增加;随着电流密度的增加,膜层厚度先增加后减小,电流密度对膜层厚度的影响取决于生长速率和反应时间。膜层厚度与电解液浓度成正比,但电解液浓度过高将引起局部烧蚀,导致膜层脱落。微弧氧化膜层能够显著提高镁合金的耐腐蚀性,膜层厚度增加和膜层孔径减小均可提高镁合金的耐腐蚀性。微弧氧化试样采用质量分数为3.5%的氯化钠溶液浸泡120 h,腐蚀速率仅为0.24 mm/a。在镁合金汽车电池箱体表面制备了微弧氧化+电泳复合膜层,微弧氧化膜层厚度约为13.7μm,电泳涂层厚度约为25μm,中性盐雾试验720 h后无明显锈蚀。To investigate the effect of electrical parameters and electrolyte concentration on the properties of Micro-Arc Oxidation(MAO)coatings on magnesium alloys,Mg-Zn series magnesium alloys are used as the research substrate.Silicate-based electrolyte is employed to prepare MAO coatings on the surface of the magnesium alloy.By varying the electrical parameters and electrolyte concentration,this paper studies the influence of different parameters on the performance of the MAO coatings.The results show that with the increase of voltage and duty cycle,and the decrease of frequency,the energy provided increases,leading to an accelerated coating growth rate and an increase in coating thickness.With the increase in current density,the coating thickness initially increases and then decreases,as the effect of current density on coating thickness depends on the growth rate and reaction time.The coating thickness is directly proportional to the electrolyte concentration;however,excessively high electrolyte concentrations can cause localized ablation,resulting in coating detachment.The MAO coatings significantly enhance the corrosion resistance of MAO samples immersed in a 3.5%sodium chloride solution for 120 h exhibits a corrosion rate of 0.24 mm/a.A composite coating of MAO followed by electrophoretic deposition is prepared on the surface of a magnesium alloy automotive battery case.The MAO coating thickness is approximately 13.7μm,and the electrophoretic coating thickness is about 25μm,withstanding a neutral salt spray test for 720 h.

关 键 词：镁合金 微弧氧化 电参数 电解液浓度 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]