Exothermal oxidation of the bottom of discharge channels upon Microarc oxidation of aluminum alloys

It has been established empirically that microarc coatings, which are produced on the surface of aluminum alloys in electrolytes that contain relatively small concentrations of chemical components (which, after plasma-chemical and thermochemical transformations, form oxides that enter into the coating), contain metalloceramic layers. The latter fact confirms that one of the main mechanisms of the growth of such coatings is the exothermal oxidation of the metallic bottom of the microarc channels leading to the evaporation of metallic components of the alloy and their transfer into the coating or onto its surface. Therefore, the color of coatings at the relatively early stage of the process of microarc oxidation is a function of the phase composition of the bottom of channels of the microarc discharge.