AZ91D alloy corrosion process

Partially protective film plays an important role in the corrosion process of AZ91D alloy [3, 4]. The corrosion process of AZ91D alloy involves three independent surface state variables area fraction of the partially protective film (0) on the alloy surface, the concentration of intermediate species Mg " (Cm), and the continuous changing of potential on P phase (fip). 

During the diffusion process, hydrogen entering the film wonld be ionized, and an MgH2 film formed on the alloy surface. As a result, the corrosion resistance of AZ91D alloy was improved. 

A schematic image of the corrosion process of magnesium alloy AZ91D. A discussion of steps (a) to (c) follows in the text. 

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