MORPHOLOGY AND PROPERTIES OF Ta2O5-CONTAINING PEO-COATINGS ON MA8 MAGNESIUM ALLOY

10.25712/ASTU.1811-1416.2023.03.003

Abstract

In the present study, the morphology, composition, and properties of coatings obtained on magnesium alloy MA8 by plasma electrolytic oxidation (PEO) in disperse electrolytes containing nanoparticles of tantalum pentoxide (β-Ta₂O₅) in various concentrations are studied. The presence of the tantalum oxide in the coatings was confirmed by X-Ray diffraction analysis and X-Ray photoelectron spectroscopy, which indicates the successful incorporation of nanoparticles from electrolyte into the coatings. It was found that with an increase in the concentration of nanoparticles in the electrolyte up to 8 g/l, an increase in the thickness from (42 ± 4) to (56 ± 7) µm and roughness parameter R_a from (2.5 ± 0.3) up to (4.7 ± 0.7) µm of coatings is observed. The highest values of microhardness (3.4 ± 0.4) GPa and Young's modulus (80 ± 12) GPa were demonstrated by coatings obtained in an electrolyte containing 4 g/l of Ta₂O₅, these values significantly exceed the values obtained for the base PEO-layer: (2.5 ± 0.3) GPa and (59 ± 10) GPa, respectively.