EFFECTS OF α-Al2O3 NANOADDITIVE ON THE PROPERTIES OF CERAMIC COATINGS PREPARED IN BORATE ELECTROLYTE BY MICRO-ARC OXIDATION

Ceramic coatings have been synthesized on 6063 aluminum alloy by micro-arc oxidation (MAO) technique in the solution of Na2B4O7 electrolyte with and without α-Al2O3 nanoadditive. Effects of α-Al2O3 nanoadditive on the phase composition, micro-structure, micro-hardness, adhesion and wear resistance of the prepared ceramic coatings have been investigated in this paper. The phase composition and microstructure of the MAO coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDX) analyses, respectively. Micro-hardness, adhesion and tribological and wear tests were also performed. The results showed that the α-Al2O3 nanoadditive doped in the electrolyte had great influence on the structural and mechanical properties of the ceramic coatings.