Methods and instruments for measuring surface morphology and mechanical parameters of oxide coatings

Morphological studies of coatings were carried out on aluminum samples obtained by microarc oxidation. The sinusoidal current density in the anodic and anode-cathode modes was 15 A/dm², and the processing time varied from  120 s to 960 s. The formation of oxide coatings occurred in a silicate-alkaline electrolyte. Studies of the surface topology and mechanical parameters of oxide coatings were carried out using an SEM, a laser profilometer and a universal electrical strength meter, which, in turn, made it possible to establish a relationship between the properties of the coatings and the sample processing time. Thus, an increase in the processing time during the micro-arc  oxidation of products made of valve group alloys leads to a complication of the surface morphology, as well as an increase in the size and number of pores. In addition, the coating roughness increases in the anode and anode-cathode modes. Electrical strength tests showed that all samples with the resulting coatings withstood a voltage of 600 V. Multifunctional coatings obtained using the developed technological modes are multilayer structures. They  consist of a base layer with excellent adhesion, an intermediate layer with porous structure and a top layer with high porosity and actively functioning surface. The changes revealed during morphological studies are characteristic of  the plasma growth model of coatings. The results of the conducted morphological studies of coatings can be implemented in the development of a digital twin of the microarc oxidation process.