Effect of electrolyte composition on micro-arc anodization of AM60B magnesium alloy

Anodic oxidation in micro-arc regime is one of the most investigated techniques used to coat magnesium alloys with ceramic coatings for protection from corrosion and wear. The anodization electrolyte composition affects the current/voltage characteristic of the cell, the anodic oxide layer morphology and its behaviour in aggressive environment. In this paper the influence of the electrolyte composition on the anodic oxidation process and oxide properties is discussed. Scanning electron microscopy, x- ray diffraction, and x- ray photoelectron spectroscopy were employed to assess morphology, crystallographic structure and composition of the anodic oxide. Electrochemical polarization tests were performed to evaluate the corrosion resistance behaviour of the coated magnesium alloys.