Novel process of electroless Ni-P plating with replacement pretreatment on magnesium alloys

In the present paper, a novel and simple pretreatment method on magnesium alloys has been described. A nickel film is formed on magnesium alloys by a replacement reaction, and it could protect magnesium alloys from excessive corrosion by plating and cleaning baths, and subsequent electroless plating could process on it successfully. This process gives no harm to the environment and prolongs the life time of the electroless bath. The nickel film and Ni-P electroless coating were studied through scanning electron microscopy, glow discharge optical emission spectrometry and electrochemical potentiodynamic polarisation. The Ni-P electroless coating on the intermediate nickel film exhibited good corrosion resistance properties in protecting the AZ31D magnesium alloy.