硅酸盐电解液中铝合金微弧氧化陶瓷膜层的结构与性能

Structure and Property of Ceramic Coating on LY12 Aluminum Alloy by Microarc Oxidation in Silicate Electrolyte

在硅酸盐电解液中利用微弧氧化方法 ,在LY12铝合金上制备了陶瓷膜层。用扫描电镜 (SEM )和X射线衍射仪 (XRD)观察分析了其形貌和相组成 ,测定了膜层厚度、显微硬度 ,并对涂层进行了耐蚀性和抗热震性研究。结果表明 ,涂层分为两层 ,外层为疏松层 ,内层为致密层 ,涂层总厚度 76μm ,致密层厚度 5 0 μm ,硬度15 0 0HV ;涂层相组成为γ Al2 O3和α Al2 O3;涂层在 30℃、10 %NaOH水溶液和 30℃、2 0 %Nacl水溶液中的耐蚀性极好。

Ceramic coating was obtained by microarc oxidation on the substrate of LY12 aluminum alloy,which phase structure and surface morphology were analyzed by SEM and XRD,the thickness and microhardness were measured,and the corrosion resistance and thermal-shock resistance were investigated.The results show that the ceramic coating is consisted of two layers with 76μm of total thickness,the hardness is 1500HV,Containing mainly γ-Al 2O 3 and α-Al 2O 3 phases,the corrosion resistances are very well in 10% NaOH aqueous solution and in 20% NaCl aqueous solution.