Abstract:

Using MAO240/750 Micro-arc Oxidation (MAO) equipment, TT260－Coating Thickness Gauge and JSM6460 Scanning Electronic Microscope, the influences of current density, duty cycle, sample dimension and solution temperature on growing rate of MAO coatings of 6061 Aluminum alloy have been investigated. The results indicate that the MAO ceramic thickness increases linearly with oxidation time; the higher the current density, the faster the growing speed of coating layer is and the higher the applied voltage at the same treatment time is. The higher voltage enhanced the ability to be broken down and to be continuous oxidized. Duty cycle nearly has no impact on the growing rate of coating. Voltage rises slightly with decreasing duty cycle. The growing speed of coating does not change with sample dimension, however the voltage increases with the increase of the sample size. The higher the temperature, the stronger the electricity conduction of solution is, and the faster the growing speed of ceramic layer is.

Key words: Micro-arc Oxidation, Aluminum Alloy, Growing Rate