摘要
本文研究了镁合金微弧氧化电解液pH值对涂层能耗及微弧氧化涂层性能的影响。通过氢氟酸调节硅酸钠‐氟化钠电解液pH值分别为10,11,12和13,以恒电流模式获得了终电压为420 V的微弧氧化涂层,表征涂层的形貌、成分、能耗和耐蚀性。研究结果表明,该微弧氧化体系的涂层单位体积能耗随着pH值升高而升高,为35~45 kJ/(dm^(2)·μm),还远称不上低能耗微弧氧化。pH值更高时,涂层厚度减小,总能耗降低,涂层均匀性和致密度提高,结合力更好,主要成分水溶性更低,耐蚀性更好。在pH值为13的电解液中获得的微弧氧化涂层的自腐蚀电流为2.88×10^(‒7)A/cm^(2),较镁合金基体降低了3个数量级。在进行低能耗微弧氧化涂层开发时,要特别注意兼顾能耗和涂层性能。
In this paper,we investigate the effect of electrolyte pH value on energy consumption and coating properties of magnesium alloy micro-arc oxidation(MAO).MAO coatings with a final voltage of 420 V were obtained by a constant current mode in the sodium silicate-fluoride electrolytes with pH value of 10,11,12,and 13 adjusted by hydrofluoric acid.The morphology,composition,energy consumption,and corrosion resistance of the coating were characterized.The research results indicate that the energy consumption per unit volume of the coating in this MAO system increases with an increase of pH value,ranging from 35~45 kJ/(dm^(2)·μm),and it is far from being called low-energy MAO.When the pH value is higher,the coating thickness decreases,the total energy consumption decreases,the uniformity and density of the coating improve,the adhesive force is better,the water solubility of the main components is lower,and the corrosion resistance becomes better.The self-corrosion current of the MAO coating obtained in an electrolyte with a pH value of 13 is 2.88×10^(-7) A/cm^(2),which is three orders of magnitude lower than that of the magnesium alloy substrate.Overall,when developing low-energy micro arc oxidation coatings,special attention should be paid to balancing energy consumption and coating performance.
作者
张雅鑫
胡勇
李信祥
刘圆敬
黄雄
刘丹
单大勇
ZHANG Yaxin;HU Yong;LI Xinxiang;LIU Yuanjing;HUANG Xiong;LIU Dan;SHAN Dayong(Institute of Corrosion Science and Technology,Guangzhou 510530,China;Guangzhou Haoyang Electronic Co.,Ltd.,Guangzhou 511400,China;Kairui Energy Saving Technology Co.,Ltd.,Shenzhen 518100,China)
出处
《现代交通与冶金材料》
CAS
2024年第3期83-90,共8页
Modern Transportation and Metallurgical Materials
基金
广州市基础研究计划(SL2022A04J00598)
广州市浩洋电子股份有限公司横向课题资助项目(E349070101)。
关键词
镁合金
轻量化
微弧氧化
能耗
耐腐蚀性
magnesium alloy
light weight
microarc oxidation
energy consumption
corrosion resistance
