ANALYSIS OF MORPHOLOGY AND MICROSTRUCTURE OF Al_2O_3 LAYERS

摘要

The paper presents the characterization of obtaining Al_2O_3 oxide layers on AlMg_2 aluminum alloy as a result of hard anodizing by the electrolytic method in a three-component electrolyte. The Al_2O_3 layers obtained on the AlMg_2 alloy in the three-component SBS electrolyte were subjected to detailed microstructural investigations (by means of a scanning electron microscope). By using X-ray diffraction, the phase compositions of obtained oxide layers were examined. It was found that the Al_2O_3 oxide layers obtained via hard anodizing in a three-component electrolyte are amorphous. The chemical composition of the Al_2O_3 layers is presented and compared with the results of stechiometric calculations for the Al_2O_3 layer. Surface morphologies of the obtained oxide layers are characterized and discussed in nano- and microscopic scales. The surface morphologies of the layers obtained have a significant influence on their properties, including their susceptibility to further modification (e.g., to incorporation of graphite), their wear resistance, and the capacity for sorption of lubricants.