Influence of irradiation intensity on corrosion properties of microarc oxidation film on AZ31 magnesium alloy with HIPIB

The purpose of this paper is to investigate the effect of high-intensity pulsed ion beam (HIPIB) intensity on the structure and corrosive properties of microarc oxidation (MAO) films on AZ31 magnesium alloy and explore the mechanism for modified anti-corrosion properties of irradiated films.,The energy deposited on the coating surface influences the remelting process of the MAO coatings significantly, which was closely related to the intensity of HIPIB; therefore, HIPIB with various intensities of 100-350 A/cm2, was selected to modify the MAO films on AZ31 magnesium alloy. The changes in film structure and phase structure of modified films were characterized by scanning electron microscopy and X-ray diffractometry (XRD) with CuKα, respectively. The corrosive behavior of the MAO films was featured with polarization curves and electrochemical impedance spectrum in 3.5 per cent NaCl solution on a PAR 2273 electrochemical workstation.,The results clearly show that a dense, continual and remelted layer with a few micrometers in thickness was obtained on the irradiated surface at 200 A/cm2, which are mainly responsible for the modified and optimal anti-corrosion property of MAO films by suppressing/retarding the process of the corrosive electrolyte infiltration into magnesium substrate surface.,The paper reveals that HIPIB irradiation could modify the corrosion resistance by producing a remelted compact layer on the MAO film surface at a suitable irradiation parameter and explored the modified mechanism of MAO films.