A composite coating for corrosion and wear protection of AM60B magnesium alloy

摘要

In this paper a protection process against corrosion and wear for AM60B magnesium alloys, by multilayer approach, is related. The coating consists of a porous oxide layer, obtained in micro-arc anodizing regime, and two or three layers deposited by sol-gel technique. The anodic oxidation pre-treatment improves the adhesion of the sol-gel layers, which are responsible for the sealing of the anodic oxide pores and for the corrosion protection effect. In addition the multilayer system significantly improves AM60B alloy wear resistance. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) were employed to assess morphology and crystallographic structure. Electrochemical polarization and wear tests were performed in order to evaluate the corrosion resistance behaviour and the wear resistance of the coated magnesium alloys.