Abstract

There are numerous studies to understand the corrosion behaviors of AZ series Mg alloys and the results on the role of β phase in the corrosion of the AZ series Mg alloys are yet contradictory. In the literature, the β phase inhibits the corrosion by barrier effect or vice versa promotes corrosion by micro galvanic coupling. This review focuses on the influence of microalloying elements and the solidification rate on the β phase morphology, affecting the corrosion behavior of AZ series Mg alloys. Additionally, the oxide film-β phase relationship on the surface of the alloys also has been evaluated on their corrosion properties.
The review showed that the contradictory evaluations of the researchers about why the β phase prevents corrosion with the barrier effect or vice versa, why the β phase increases corrosion with micro galvanic coupling, attributed to variations in the production methods and related β phase morphology in microstructure.

Keywords: Mg alloy; AZ series; Intermetallic; Corrosion