Effects of Power Modes on Properties of Micro-Arc Oxidation Biological Coatings on Magnesium Alloy

At present，there are few studies on the preparation of biological coatings by micro-arc oxidation under different power modes.In this work，micro-arc oxidation (MAO) process was carried out on the surface of ZK60 magnesium alloy to prepare the biological coatings by means of four different power modes (full stage constant voltage mode，full stage constant current mode，constant voltage-constant current mode，constant current-constant voltage mode).The changes of voltage/current with time in the reaction process under different power supply modes were real-time recorded and analyzed，and the phase，microstructure，element distribution，surface roughness and contact angle of the MAO biological coatings obtained under different power supply modes were investigated by means of scanning electron microscope (SEM)，energy dispersive spectrometer (EDS)，Diffractometer (XRD) and Confocal microscopy.Results indicated that the phase constituents of the coatings prepared under four power modes included Mg，MgO and calcium-phosphoru