电解液pH值对镁合金微弧氧化能耗及涂层性能的影响
Effect of electrolyte pH value on energy consumption and coating properties of magnesium alloy micro-arc oxidation
张雅鑫 1胡勇 2李信祥 3刘圆敬 1黄雄 1刘丹 1单大勇1
作者信息
- 1. 广东腐蚀科学与技术创新研究院,广东 广州 510530
- 2. 广州市浩洋电子股份有限公司,广东 广州 511400
- 3. 深圳市开瑞节能科技有限公司,广东 深圳 518100
- 折叠
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/(dm2·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/cm2,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.
Abstract
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 con-sumption,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/(dm2·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 de-creases,the uniformity and density of the coating improve,the adhesive force is better,the water solu-bility 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/cm2,which is three orders of magnitude lower than that of the magnesium alloy substrate.Overall,when de-veloping low-energy micro arc oxidation coatings,special attention should be paid to balancing energy consumption and coating performance.
关键词
镁合金/轻量化/微弧氧化/能耗/耐腐蚀性Key words
magnesium alloy/light weight/microarc oxidation/energy consumption/corrosion resistance引用本文复制引用
基金项目
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(E349070101)
出版年
2024
NETL
NSTL
万方数据