Cailiao Baohu (Jun 2022)

Preparation and Corrosion Behavior of Rare Earth Oxide Chemical Conversion Membrane for AZ31 Magnesium Alloy by Ultrasonic Assisted Process

  • XIAO Fei - yan, RAN Xiao - xiao, LIU Jing, XIANG Qing, YANG Feng

DOI
https://doi.org/10.16577/j.issn.1001-1560.2022.0160
Journal volume & issue
Vol. 55, no. 6
pp. 92 – 97

Abstract

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Aiming at improving the corrosion resistance of AZ31 magnesium alloy in 3.5% (mass fraction) NaCl solution, the effects of CeO2 concentration and ultrasonic and non - ultrasonic assisted processes on chemical conversion film of AZ31 magnesium alloy prepared in the mixed bath of 0.300 mol/L Na2MoO4+0.120 mol/L NaF +0.050 mol/L Na3PO4+0.075 mol/L K2FeO4 were studied. In addition, the influence of the chemical conversion film on the corrosion resistance of AZ31 magnesium alloy was also studied. Results showed that in the case of ultrasonic assisted process, when the coating was prepared with an addition of 0.050 mol/L CeO2 in the mixed bath, the corrosion potential of magnesium alloy shifted to be more positive and the corrosion current density decreased significantly. After 96 h immersion in 3.5% NaCl solution, the surface of magnesium alloy was still relatively smooth without obvious cracks, indicating that the magnesium alloy substrate was effectively protected.

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