Study on Electroless Ni-P Alloy Plating on Magnesium Alloy into Neutral Plating Bath

The pretreatment without chrome and the technics of electroless Ni-P alloy plating into neutral plating bath was investigated. By means of optical instrument of image analysis、GDS、electronic balance and XRD,the paper studies on cross-section morphology、plating rate、component and phase structure of electroless Ni-P alloy plating on magnesium alloy. It indicates that the planeness of plating layer and the smoothness of structure before plating have an intimate relation. Phosphorus content of plating layer which is between 9.5%～11% is amorphous structure,but after drawing temper the electroless plating layer starts crystallization at 300 ℃ or so,the crystallization process can almost finish at 400 ℃. In addition,the investigation shows that temperature has an obvious influence for plating rate,and complex agent also have timing characteristic.