反应时间对LY12铝合金微弧氧化膜层组织及性能的影响

在K₂ZrF 电解液体系中, 利用微弧氧化方法在LY12铝合金表面制备了氧化锆陶瓷膜. 结果表明, 膜层主要由t-ZrO₂、m-ZrO₂组成, 还含有少量的γ-Al₂O₃和KZr₂(PO₄)₃. 随着反应时间的延长, 膜层晶相物质的含量增多; 膜层表面粗糙度增大, 致密性提高; 膜层的厚度近似线性增加, 硬度增大, 耐腐蚀性提高, 抗热震性减弱. 磨损实验表明, 带有氧化锆陶瓷膜的试样耐磨损性能大幅度提高, 铝合金的摩擦系数约为膜层的2/3, 随着反应时间的延长膜层的磨损量先降低后升高, 摩擦系数减小.

nfluence of Treatment Time on Structure and Property of Ceramic Coatings Formed on LY12 Aluminum Alloy by Micro-arc Oxidation

In K₂ZrF6 solution, the ceramic coatings composed of a large amount of t-ZrO₂, m-ZrO₂ and a little γ-Al₂O₃ and KZr₂(PO₄)₃ were prepared on LY12 aluminum by a micro-arc oxidation technique. With the increase of micro-arc oxidatin (MAO) time, the content of crystalline substances is increased, the coating surface roughness is increased, and the compactness of the coating is improved. The thickness of the coating is increased approximately linearly, and the hardness and the corrosion resistance are both improved, while the heat shock resistance of the coatings turned worse. Meantime, the friction tests show that the anti-abrasion of the coated samples is improved to a large extent, the friction coefficient of the substrate is about 2/3 that of the coated samples. With the increase of MAO time, friction weight loss of the coated samples is first increased, and then decreased, while the friction coefficient is decreased.