Preparation, interface properties and corrosion behavior of nano-modified MAO ceramic film on 5B70 Al alloy

Ceramic film with graphite oxide (GO) particles were prepared on 5B70 Al alloy by micro-arc oxidation(MAO) technique. Effect of GO concentrations on the micro-arc oxidation behavior, ceramic/metal interfacial characteristic and the anti-corrosion performance of MAO ceramic films was studied. The experimental results indicated that the GO additive could decrease the breakdown voltage, enhance the MAO reaction, decrease the surface roughness, reduce the porosity, increase the film thickness, and improve the ceramic/metal interface adhesion. The MAO ceramic film prepared in the electrolyte with 0.15 g/L GO additive had the best corrosion resistance in 3.5 wt% NaCl solution, as manifested by a corrosion current density of 3.72 x 10(-8)A center dot cm(-2) that was 2 orders of magnitude less than that of the 5B70 Al alloy substrate. The same results of corrosion resistance were also verified by immersion corrosion test.

Automated summary

Ceramic films with graphite oxide particles were prepared on an aluminum alloy using the micro-arc oxidation technique. The addition of graphite oxide improved the corrosion resistance and adhesion of the ceramic film to the metal substrate.