Effects of Ce(NO₃)₃ concentration on microstructure and properties of plasma electrolytic oxidation layer on 6061 alloy

Abstract Plasma electrolytic oxidation treatment of 6061 Al alloy was carried out in a sodium silicate and hydroxide alkaline electrolyte containing different concentrations cerium nitrate (Ce (NO 3 ) under constant current mode. The effects Ce concentration on the roughness, cross section surface morphology, composition phase composition, adhesion force corrosion resistance prepared layer were studied by means true color microscope, scanning electron x-ray energy spectrometer, diffractometer, micrometer scratcher electrochemical workstation. results show that with increase Ce(NO electrolyte, thickness plasma increases gradually, micropores cracks increase, roughness first then decreases. layers are mainly composed α -Al 2 O , γ small amount SiO 5 . element is present form mixture Ce(OH) 4 CeO .The reduces binding strength between matrix, self-corrosion potential, decreases current, weakens resistance. 0.25 g l −1 has less cracks, better compactness. bonding substrate 27 N, density 3.42 × 10 −9 A cm −2 potential −0.72 V, best presented.