Effects Of Fe2+ Content On Properties Of Mao Films On 2a12 Aluminum Alloys

In order to obtain a high absorption and high emission thermal control film by making out the effect of doping element on thermal control properties, the micro-arc oxidation (MAO) film was prepared by using a phosphate system and Fe2+ salt additive. The effects of different concentrations of Fe2+ salt additive on the thermal control performance of MAO film was studied. The effects of Fe2+ concentration on the microstructure, membrane composition and salt spray corrosion resistance of MAO were investigated by XRD and EDS, respectively. The results show that Fe2+ enters into the film, and its content increases with the increase of Fe2+ concentration in the additive. The solar absorption ratio and emissivity firstly increase and then descend, and the peak appears at the Fe2+ concentration of 20 g/L, with the values of 0.89 and 0.83, respectively. The addition of Fe2+ leads to form Fe3O4, which significantly increases the salt spray resistance time and thermal control property. When the concentration of Fe2+ is 20 g/L, 2A12 micro-arc oxidation film has the best thermal control properties (alpha(S) is 0.89 and epsilon(H) is 0.83) and corrosion resistance.