Performance evaluation of scanning micro-arc oxidation ceramic coating on aluminum alloy under different current working modes

Micro-arc oxidation is a conventional surface treatment technology. Usually, the workpiece is placed in an electrolyte for oxidation to improve its surface properties. However, this method has obvious limitations, namely, it is difficult to effectively process large workpieces, or the processing process may not be convenient enough. To solve this problem, this paper proposes a non-immersion micro-arc oxidation process, namely scanning micro-arc oxidation, which uses a three-axis slide to control the cathode movement for scanning micro-arc oxidation without immersing the sample metal in the electrolyte. At the same time, scanning micro-arc oxidation is performed by adjusting the working mode of the power supply, and the effect of the current mode on the performance of micro-arc oxidation ceramic coatings is studied. The relationship between the current mode and the thickness, hardness, wear resistance, and corrosion resistance of the ceramic coating is revealed through various characterization techniques. Using a three-axis slide to realize scanning micro-arc oxidation and explore the performance of micro-arc oxidation ceramic coatings under different current modes is expected to optimize the micro-arc oxidation process in specific application scenarios.