The effects of the additives of Na 2WO 4 and SiC powder in the electrolyte on the microstructures and properties of ceramic coatings produced by Micro-Arc Oxidation on Al-alloy surfaces have been investigated. The results show that, Na 2WO 4 additive can not only inhibit the formation of the porous layer in ceramic coatings, but also improve the phase-microstructures and wearing resistance of the coatings; SiC particles further improve the wearing resistance of the coatings by means of permeating the ce...