At present, the surface corrosion prevention technology of magnesium alloy in industrial production generally has the following four methods  or their combination.

1.Chemical conversion coating

2.Organic high polymer coating

3.Anodizing

4.Electroplating and electroless plating                            

 

The difficulties of electroplating and electroless plating on magnesium alloy

1. The standard electrode potential of magnesium is very low (-2.36v), which is even more negative than aluminum.it will happen a intense replacement reaction when the high chemical activity of magnesium alloy meet the metal ions in the plating bath,the replacement substance is loose, rough. The coating adhesion will be seriously affected.

2. Due to different composition elements and surface states of magnesium alloys  type, and a large number of IMC, which lead to uneven potential distribution on the surface of the material and affect the uniformity of the coating.

3.The pores, gaps, cracks, loose, segregation on magnesium alloy surface  will affect coating adhesion.

4.Electroplating or electroless plating on magnesium alloy all are negative polarity coating, in order to effectively prevent the corrosion of magnesium alloy, the coating must be non-porosity, otherwise, the formation of corrosion battery between magnesium alloy and coating will not effectively protect of material ,it may increases the corrosion.     


Electroless nickel plating is one of the most effective protective methods for magnesium alloys, it can improve corrosion resistance, wear resistance and other properties, also could be used as bottom coating, intermediate layer or surface layer, the coating is uniform and dense.

Magnesium alloy electroless nickel plating has  aready widely used in military and civil products.