The mechanism of formation of composite microarc coatings on aluminum alloys

It is shown that heating of an internal layer of microarc coating up to temperatures at which insignificant rates of heat removal from microdischarges that possess a temperature of no less than 1200°C are ensured leads to realization of a sufficient time interval for the occurrence of almost 100% transformation of low-temperature aluminum-oxide modifications into high-temperature ones. Insufficient heating of a number of areas of the coating to these temperatures is the main reason for formation of a composite microarc coating that contains both low- and high-temperature aluminum-oxide modifications in its internal layer.