Enhance corrosion behavior of AZ31 magnesium alloy by tailoring the anodic oxidation time followed by heat treatment in simulated body fluid

Abstract

Purpose This paper aims to investigate the impact of anodizing time and heat treatment on morphology, phase and corrosion resistance of formed coating. To characterize the anodic oxide layer, X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) that was equipped with energy dispersive spectroscopy (EDS) was hired. The corrosion behavior of oxide-coated samples was estimated by electrochemical polarization test in simulated body fluid (SBF). Design/methodology/approach Anodic oxidation method is applied to reinforce the corrosion and biological properties of biomaterials in the biomedical industry. In this paper, the alkaline NaOH (1 M) electrolyte was used for AZ31 magnesium alloy anodizing accompanied by heat treatment in the air. Findings It can be concluded that the best corrosion resistance belongs to the 10 min anodic oxidized sample and among the heat-treated samples the 30 min anodized sample represented the lowest corrosion rate. Originality/value In this study, to the best of the authors’ knowledge for the first time, this paper describes the effect of anodizing process time on NaOH (1 M) electrolyte at 3 V on corrosion behavior of magnesium AZ31 alloy with an alternate method to change the phase composition of the formed oxide layer. The morphology and composition of the obtained anodic oxide layer were investigated under the results of SEM, EDS and XRD. The corrosion behavior of the oxide coatings layer fabricated on the magnesium-based substrate was studied by the potentiodynamic polarization test in the SBF solution.