▎ 摘　　要

NOVELTY - An electrolyte solution comprises 5-50 g/L main film-forming agent, 1-30 g/L co-film-forming agent, 1-20 g/L main coloring salt, 1-20 g/L complexing agent and deionized water. The main film forming agent is potassium silicate and/or sodium silicate. The co-film forming agent is potassium hydroxide, sodium hydroxide, potassium fluoride, sodium fluoride, potassium fluorosilicate, sodium fluorosilicate, sodium borate, potassium borate and/or sodium metaaluminate. The main coloring salt is copper sulfate, copper acetate, copper pyrophosphate and/or basic copper carbonate. The complexing agent comprises condensed phosphate, organic phosphonate and tartrate. The condensed phosphate is pyrophosphate, tripolyphosphate and/or polyphosphate. The acid salt is ethylenediamine tetramethylene phosphonate and/or diethylenetriamine pentamethylene phosphonate. The mass ratio of polycondensation phosphate, organic phosphonate and tartrate is 1:1:1-2. USE - The electrolyte solution for anodising used for magnesium alloy surface micro-arc oxidation. ADVANTAGE - The electrolyte solution for anodising is not easy to precipitate in micro-arc oxidation process, has high stability, long service life, high film forming efficiency, high blackness, small chromatic aberration, low surface roughness of coating layer, high hardness, good corrosion resistance, strong adhesion, not easy to decolor, and excellent thermal control performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation black coating on the surface of magnesium alloy by using the electrolytic solution for magnesium alloy surface micro-arc oxidation comprising polishing magnesium alloy substrate, removing oil stains, taking main coloring salt, co-coloring salt and complexing agent, dissolving in deionized water to obtain an metal complex aqueous solution, adding remaining electrolyet solution raw materials, stirring for 5-10 minutes, standing for 10-20 minutes, obtaining electrolyte solution, using magnesium alloy substrate as anode, graphite plate or stainless steel plate as cathode, pouring electrolyte solution into the electrolytic cell, immersing anode, performing micro-arc oxidation treatment for 3-60 minutes, taking out magnesium alloy substrate, ultrasonic cleaning with ethanol and purified water, and drying with cold air.