Corrosion and wear resistant polyp-xylene composite coating on AZ31 magnesium alloy prepared by micro-arc oxidation and vapor deposition

To improve the wear and corrosion resistance of magnesium alloy, a multifunctional organic/inorganic hybrid coating was prepared on AZ31 magnesium alloy by microarc oxidation and vapor deposition of Polyp-xylene (MAO-PPX). Electrochemical tests show that the MAO-PPX composite coating can effectively block the corrosive medium and improve the corrosion resistance of magnesium alloy. Long-term corrosion protection was confirmed by neutral salt spray tests at 35 degrees C with 5 wt% NaCl. In addition, the MAO-PPX composite coating demonstrated a much lower friction coefficient which could be attributed to the polyp-xylene filled in the micropores of the MAO layer and transferred on the counterpart sphere. This composite coating with excellent anticorrosion and decent lubricating properties has broad application prospects in surface protection of magnesium alloys.