Characterization of oxide coating grown by plasma electrolytic oxidation (PEO) at different times on aluminum alloy AA2024-T3

Abstract

Plasma oxide coatings have superior physical and chemical properties than films generated by conventional anodizing, besides only required a few seconds procedures and using environmentally friendly electrolytes. In this work, an experimental system was used to generate oxide films in substrates of aluminum alloy (AA2024-T3), varying treatment time in an alkaline solution. SEM/EDS characterizations were performed; also, other tests as profilometry; Eddy Current; XRD and ATR-FTIR. In the coating generated by 210 s, the morphology presented better uniformity and thickness of 1.3 μm. By XRD analysis, peaks related to Al, ɣ-Al2O3, mullite and amorphous phases. The main functional groups detected in the films were O–H, C=O, and bands related to alumina. Graphical abstract: [Figure not available: see fulltext.]