Electrochemical Study of Sintered Aluminum-Based Materials and MAO Coatings on Their Surfaces

The electrochemical behavior of sintered materials from powder aluminum, its compositions with copper (1, 2, and 3%), and coatings on their surfaces formed by micro-arc oxidation (MAO), is studied in a 3% NaCl solution. The values of the anodic and cathodic current densities on the polarization dependences for compact aluminum samples are approximately 4 and 2 times lower compared to sintered powder aluminum, which, in turn, is less corrosive than aluminum-copper composites. MAO coatings lead to a decrease in anodic and cathodic currents, which indicates their positive effect on the corrosion resistance of these materials. Using scanning electron microscopy and X-ray phase analysis, the structure of aluminum-copper composites with MAO coatings after electrochemical studies is examined.