镁合金表面铈氧化物陶瓷涂层的腐蚀特性及机理研究

Corrosion Resistance and Mechanism of Cerium Oxide Ceramic Coatings on Magnesium Alloys

采用溶胶.凝胶法在AZ91D镁合金表面制备无毒、无污染的CeO_2陶瓷涂层。探讨了CeO_2耐蚀涂层的制备工艺过程,通过正交实验确定了最佳工艺参数;腐蚀实验结果表明,CeO_2陶瓷涂层可以显著提高镁合金基体的耐蚀性。采用SEM对膜层形貌进行了观察,发现薄膜对基体的覆盖度较高,膜层完整,与基体的结合力较强;用XRD,XPS对表面层物相和元素组成进行了测定,结合其它实验结果提出并讨论了镁合金表面CeO_2陶瓷膜的形成机制以及膜层对基体耐蚀性影响的机理。

To improve the corrosion resistance of the magnesium alloy AZ91D widely applied in both the aviation and aerospace industry, a kind of nontoxic CeO2 films were deposited via the Sol-gel methods environmental friendly. This paper probed into the techniques of the Sol-gel process and the optimal parameters were predicted through a series of orthogonal experiments. The experimental testing outcomes indicated that the corrosion resistance of AZ91D substrates was greatly enhanced after being coated by the CeO2 ceramic films. Morphology observation of the coatings were conducted by SEM, and it was found that the coverage were dense and intact with a mighty cohesion without obvious exfoliation. The surface phase formation were evaluated by XRD and XPS, while the formative mechanism of CeO2 ceramic coatings as well as their effects on the corrosion resistance of the AZ91D substrates were investigated thoroughly based on the all the experimental evidences.