Investigation of hybrid composite coating on ZA-27 alloy produced by MAO

In this paper, the steps in the production process of forming hybrid composite coatings on surface of the ZA-27 alloy known as a sliding bearing material, and analysis of surface morphology of the coated samples were investigated. The process includes forming an electrolytic solution with solid lubricant particles content in a stainless steel tank and coating procedures that called micro arc oxidation (MAO). The substrate materials used in this study are commercial ZA-27 alloy that produced by using die-casting method. Two different electrolytic solutions were used for the surface coating process. Electrolytic solutions include solid lubricant particles (graphite and hexagonal boron nitride (h-BN)). The results showed that both graphite/Al2O3 and h-BN/Al2O3 hybrid composite coating were successfully grown on surface of the ZA-27 alloy. The structural and chemical compositions of the both coated samples were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffraction (XRD). In the meantime, coating thickness were also determined.