Mg-Li合金微弧氧化陶瓷膜的制备及其耐蚀性能

Corrosion resistance property of micro-arc oxidation coatings on Mg-Li alloy obtained in different systems

通过三种优化工艺体系在Mg-5%Li合金表面上生长陶瓷膜层,分析了膜层的厚度、显微结构、相组成和耐蚀性.结果表明,三种膜层都含有MgO相,微弧氧化试样的耐蚀性能都明显提高.使用Na_3PO_4体系制备的膜层含有MgF_2,膜层最厚、表面有大量裂纹;使用Na_2SiO_3体系制备的膜层含有橄榄石型Mg_2SiO_4,耐点蚀性能最好;使用Na_2SiO_3-Na_3PO_4体系制备的膜层含有MgSiO_3,致密性最好,膜层耐均匀腐蚀性能最好.

Ceramic coatings were prepared on the surface of Mg-5%Li alloy in three kinds of optimized electrolytes by single-polar pulsed micro-arc oxidation （MAO）. Thickness, microstructure, phase composition and corrosion resistance of the ceramic coatings were investigated. The results showed that all the MAO coatings were composed of MgO, and their corrosion resistance was improved distinctly. The coating gained in Na3PO4 system contained MgF2, and was the thickest with a great deal of cracks; the coating from Na2SiO3 system included olivine Mg2SiO4, and had the best pitting corrosion resistance; the coating from Na2SiO3-Na3PO4 system contained MgSiO3, showed the most compact micro-surface, and owned the best uniform corrosion resistance.