Preparation of Micro-Arc Oxidation Thermal Control Films on LA141 Mg-Li Alloy Surface

A micro-arc oxidation thermal control film was prepared on the surface of LA141 Mg-Li alloy. Optical microscope, scanning electron microscope, X-ray diffractometer (XRD) and radiometer were used to analyze the surface morphology, composition and thermal control performance of the film. The results showed that after pickling pretreatment, the surface micro-area structure of LA141 Mg-Li alloy was uniform and flat. When the oxidation termination voltage was 300-350 V, a smooth, uniform and dense micro-arc oxidation thermal control film could be obtained with a pore size less than 5 mm, The film was an amorphous ceramic film composed of magnesium, oxygen, phosphorus, fluorine, lithium and a small amount of aluminum. The thermal control performance and thickness of the film increased with the increase of oxidation termination voltage. When the oxidation termination voltage was about 350 V, the overall performance of micro-arc oxidation thermal control film was the best.