Effect study of Mao-coatings heat treatment on their structure, phase composition, physical and mechanical properties

Abstract

The structure, phase composition and physical and mechanical properties of MAO-coatings on deformable aluminum alloys after heating with subsequent holding were studied. It is revealed that in the temperature range from 50 to 600C in MAO-coatings there are changes of three types, manifested in increasing the porosity of MAO-coatings and increasing the content of substances with higher physical and mechanical properties. It is shown that the surface hardness, wear resistance and electrical resistance of MAO-coatings increase, but the breakdown voltage decreases. It is established that the simultaneous happens of changes of different types leads to an increase in number of cracks and ruptures in the structure of MAO-coatings and a decrease in their physical and mechanical properties. To maximize the surface hardness, wear resistance and electrical resistance of MAO-coatings, it is proposed to conduct their heating with sequential stepped holding, ensuring a consistent implementation of changes of all three types.