三种不同电解液中镁微弧氧化膜研究

Study on Micro-Arc Oxidized Coatings on Magnesium in Three Different Electrolytes

摘要:

在氟锆酸盐、铝酸盐和硅酸盐3种不同电解液中对镁进行微弧氧化处理分别制得了锆膜、铝膜和硅膜, 对这些膜层的形貌、相组成、表面粗糙度、结合强度、硬度和耐蚀性进行了研究。结果表明：锆膜致密，由t-ZrO2、MgF2和Mg2Zr5O12相组成；铝膜多孔，由MgAl2O4和MgO相组成；硅膜多孔，由Mg2SiO4和MgO相组成。这些膜层表面很粗糙，膜层与基体结合非常牢固。铝膜的硬度比锆膜和硅膜更高。经微弧氧化处理后镁的耐蚀性得到了明显改善，其中锆膜的耐蚀性最好。

Abstract:

Three micro-arc oxidization coatings were prepared on magnesium substrates in fluorozirconate electrolyte (Zr-coating), aluminate electrolyte (Al-coating) and silicate electrolyte (Si-coating). Morphologies, phase components, surface roughness, bonding strength, hardness and corrosion resistance of the coatings were investigated. The results show that the Zr-coating is dense and mainly composed of tetragonal ZrO2 (t-ZrO2), MgF2 and Mg2Zr5O12. The porous Al-coating is mainly composed of MgAl2O4 and MgO. The Si-coating is porous and mainly consists of Mg2SiO4 and MgO. The coatings formed in the three electrolytes reveal relatively coarse surface and are bonded tightly to the substrates. The Al-coating possesses a higher hardness than the Si-coating and the Zr-coating. The corrosion resistances of the coatings on magnesium surface are obviously superior to that of the pure magnesium substrate in the NaCl solution, and the Zr-coating shows the best corrosion resistance.