Corrosion damage estimation of microstructure of electric arc coating of Al-Mn Alloy in the initial state and with PEO coatings

The effect of electric arc coating Al-Mn alloy microstructure on the surface corrosion damage after annealing at different temperatures and with synthesized PEO coatings has been investigated. The dependencies between the changes in the size of the structural components of the alloy Al-Mn and corrosion resistance of the alloy with the PEO coatings in the environment of synthetic weak acid rain (pH 4.5). It is shown that the annealing temperature is 200°C, and especially 550°C cause a substantial increase of surface defects in comparison to annealing at temperatures of 400°C and 500°C. This is due to the lack of a positive influence of manganese during annealing of 200°C, and increasing the size of the cathode inclusions at an annealing temperature of 550°C. Its results in the formation PEO layers with high porosity. Image processing method for corrosion damage estimation of microstructure of electric arc coating of Al-Mn alloy is proposed.