Effect of annealing treatment on microstructure of micro arc oxidation ceramic film on Al-Mg-Sc alloy

The effect of annealing treatment on the microstructure of micro arc oxidation (MAO) ceramic film prepared on Al-Mg-Sc alloy was studied. Results suggested that the difference of microstructure of Al-Mg-Sc alloy after various ageing treatment mainly focused on the evolution of dislocation density and the precipitation of beta phase (Al3Mg2), and this difference induced the component transformation of surface oxide film from Al2O3 and MgO to MgO and MgAl2O4.Meanwhile, when the other parameters were kept constant, the relevant relations between the microstructure evolution and precipitation phase and the substrate induced the changes of electrical conductivity, then determining the characteristics of MAO ceramic film. Without sacrificing any strength, the optimal MAO ceramic film owning the higher thickness and lower porosity was obtained on Al-Mg-Sc alloy after annealing treatment at room temperature, and tightly bonded to the substrate, which provided a theoretical basis for subsequent research to improve the corrosion resistance of Al-Mg-Sc alloy.

Automated summary

The effect of annealing treatment on the microstructure of micro arc oxidation (MAO) ceramic film prepared on Al-Mg-Sc alloy was investigated. The results showed that the difference in the microstructure of the alloy after various annealing treatments mainly focused on the evolution of dislocation density and the precipitation of beta phase (Al3Mg2), leading to a transformation in the composition of the surface oxide film. The optimal MAO ceramic film with higher thickness and lower porosity was obtained on the alloy after annealing treatment at room temperature, providing a theoretical basis for improving the corrosion resistance of Al-Mg-Sc alloy.