Magnesium alloy-surface hydrophobic composite film and preparation method thereof

The invention discloses a magnesium alloy-surface hydrophobic composite film and a preparation method thereof. The composite film comprises a micro-arc oxidation film and an organic coating film. The preparation method comprises the steps: grinding, polishing, washing, degreasing, ultrasonically washing magnesium alloy and other pretreating; configuring a micro-arc oxidation solution, and conducting micro-arc oxidation on the pretreated magnesium alloy to form a micro-arc oxidation film; utilizing a CHI860D electrochemical workstation, using micro-arc oxidized magnesium alloy as a working electrode, a platinum electrode as an auxiliary electrode, and a saturated calomel electrode as a reference electrode, and electrolyte being 1 to 5 ml/L of aqueous triethanolamine solution; organically film-coating the surface of the micro-arc oxidation film of magnesium alloy by a chronopotentiometry, and taking out the magnesium alloy to be dried for 1-2 hours at a temperature of 70 to 80 DEG C to obtain a magnesium alloy-