纳米TiO_2掺杂对AZ91D镁合金微弧氧化膜形貌及性能的影响

Effects of Doping of Nano-TiO_2 on Morphology and Properties of Micro-arc Oxidation Film on AZ91D Magnesium Alloy Surface

在NaAlO2-Na3PO4复合电解液体系中,用微弧氧化技术在AZ91D镁合金表面原位制备了一层致密的氧化膜,分析了纳米TiO2加入对该膜表面形貌、物相、耐腐蚀性能和摩擦磨损性能的影响。结果表明:电解液中不加入纳米TiO2制备的微弧氧化膜表面疏松多孔,由MgAl2O4、Mg3(PO4)2、MgO以及Mg相构成,并以MgAl2O4相为主;加入纳米TiO2后,膜层表面变得致密,膜层中增而加了TiO2相;与基体相比,两种微弧氧化膜的耐腐蚀性和耐磨性均显著提高,加入纳米TiO2制备微弧氧化膜的耐腐蚀性和耐磨性更好。

Micro-arc oxidation technology was used to prepare a dense ceramic film on the surface of AZ91D magnesium alloy in NaA102-Na3PO4 composite electrolyte system, and then the impacts of doped nano-TiO2 on the microstructure, phase composition, corrosion resistance and friction and wear property of the film were analyzed. The results show that the micro-arc oxidation film prepared without nanc^TiO2 powders had a loose and porous surface, and was composed of MgA1204, Mg3 （PO4）2, MgO and Mg, in which the MgAI204 phase accounted for the most. In addition, the surface of micro-arc oxidation film became dense and a new phase of TiO2 appeared after adding nano-TiO2 powders into the electrolyte in preparation. Compared with the matrix of AZ91D magnesium alloy, the corrosion resistance and abrasive resistance of two oxidation films all increased significantly, especially for the film doped nano-TiO2 in preparation, which had the best corrosion resistance and abrasive resistance.