Rezumat
CZU 544.63; 544.65
DOI https://doi.org/10.5281/zenodo.3522285
The growth kinetics of plasma electrolytic oxide coatings on a coarse grained and ultrafine-grained biodegradable Mg-2%Sr alloy was evaluated. Kinetic coefficients corresponding to the coating growth according to the dissolution-precipitation model were estimated depending on the alloy structure, and their correlation with the coating properties was demonstrated. The coating morphology and phase composition were correlated with protective properties studied using electrochemical tests on treated and untreated samples in Ringer's solution. Equivalent circuits for the systems “alloy-electrolyte” and “alloy-coating-electrolyte” were developed. It was shown that a PEO coating obtained on an ultrafine-grained alloy has the best protective properties.
Keywords: plasma electrolytic oxidation, coating growth kinetics, biodegradable alloy, corrosion, equivalent circuit.