Surface Modification of AZ91 Magnesium Alloy

Mg is the lightest structural metal with the highest specific strength. It is therefore considered as a solution for vehicular mass reduction so as to reduce the fuel consumption and greenhouse gas emission. Unfortunately, Mg and its alloys are highly susceptible to corrosion, particularly in salt-spray conditions. This has limited its use in the automotive and aerospace industries, where exposure to harsh service conditions is unavoidable. To improve its corrosion resistance it is viable to apply a desirable engineering coating on the Mg surface.This communication discusses the practical aspects of magnesium surface modification based on our review. A novel immersion coating process is also discussed along with the corrosion behavior of coated and uncoated AZ91 magnesium alloy.