▎ 摘　　要

NOVELTY - A coating method of graphene oxide and micro-arc composite film on surface magnesium alloy comprises pre-processing magnesium alloy using No. 180 silicon carbide (SiC) sand paper, No. 1000 SiC sand paper and No. 2000 SiC sand paper, grinding, and ultrasonic processing magnesium alloy in acetone at acoustic power of 200-300 W for 3-10 minutes; electric blowing and drying and performing micro-arc oxidation; and coating surface comprising microarc oxidation ceramic film layer. USE - Coating method of graphene oxide and micro-arc composite film on surface magnesium alloy. ADVANTAGE - The method reduces corrosion current of composite film layer to 14.5nA/cm2. DETAILED DESCRIPTION - Coating method of graphene oxide and micro-arc composite film on surface magnesium alloy comprises: (A) pre-processing magnesium alloy using No. 180 silicon carbide (SiC) sand paper, No. 1000 SiC sand paper and No. 2000 SiC sand paper, grinding, and ultrasonic processing magnesium alloy in acetone at acoustic power of 200-300 W for 3-10 minutes; (B) heating treated magnesium at 60-75 degrees C with 40-50 g/L sodium hydroxide (NaOH) solution for 10-20 minutes and 10- 20 g/L sodium phosphate solution for 10-20 minutes to obtain a sodium phosphate solution treatment of magnesium alloy; (C) using distillation water and washing, electric blowing and drying; (D) performing micro-arc oxidation; (E) arc surface treating magnesium alloy with ceramic oxidation film layer using electrolytic liquid; (F) taking natural graphite powder and adding mixed acid of sulfuric acid and saltpeter acid, stirring at 80-150 revolutions/minute, adding potassium permanganate and reacting for 2-3 hours; and (G) coating surface comprising microarc oxidation ceramic film layer. The micro-arc oxidation step comprises removing oil and magnesium alloy, putting into stainless steel electrolytic groove installed with electrolyte, removing magnesium alloy power source and connecting positive pole, using pulse micro-arc power supply at current density of 0.5-0.8 A/dm2, duty ratio of 10-40% and frequency of 500-2000 Hz for 5-15 minutes. The electrolytic liquid comprises 20-40 g/L sodium silicate, 3-8 g/L sodium fluoride, 1-5g/L potassium hydroxide, and water.