By having zinc, aluminium, magesium or a combination coating on the base steel substrate, we can prevent the steel from rusting. The metals will help to prevent oxygen and water from reaching the steel substrate by acting as a barrier. In the event that oxygen and water reaches the steel substrate, the metal coatings (Zinc, Aluminum and Magnesium) being more reactive than iron, will then act as a sacrificial metal and oxidises (ie. corrode) in place of the steel substrate.

Benefits of having Magnesium in alloy protective coating

• The addition of magnesium which is a much more reactive metal, to protective coatings helps to increase the corrosion resistance of the steel. Please refer to chart below which depicts the reactivity of different types of metals.
• Magnesium possesses high strength to weight ration which will help to realise light weight construction. Therefore, magnesium metal is commonly added to steel alloys for use in various light weight applications such as aircrafts, automobiles and electronics.