Micro-arc oxidation ceramic(MAO)coating was prepared on AZ91 magnesium alloy from a silicate alkaline solution composed of 5.0~ 30.0g/L Na2 SiO3,1.0-5.0 g/L NaOH,5.0-8.0 g/L KF,0.5~2.0 g/L Na3C6H5Q7,and 0.5~2.0 g/L ethylene diamine tetraacetic acid(EDTA),in alternating current galvanostatic mode and at a cur-rent density of 20-50 A/dm2.The surface and cross-section morphologies of the MAO coating were observed using a transmis-sion electron microscope(TEM)and scanning electron micro-scope(SEM),and the mecha...