Electroless Ni-P plating on AM60B magnesium alloy via maleic acid conversion coating as pretreatment layer

Corrosion resistance of the AM60 Magnesium alloy must be improved before any outdoor application. The corrosion resistance of the magnesium alloys can be significantly increased by electroless Ni-P plating. Electroless plating of the magnesium alloys needs suitable pre-treatment process due to their high electrochemical activity. In this study, maleic acid conversion coating as environmentally-friendly pretreatment layer was used in order to electroless Ni-P plating of the magnesium alloy to replace the toxic and dangerous chromating process. Morphology, composition and microstructure of the Ni-P coating were investigated by Scanning Electron Microscopy (SEM), Energy Dispersive x-ray Spectroscopy (EDS) and X-Ray Diffraction (XRD) methods. The results showed that the maleic acid pre-treatment is suitable process for application of the Ni-P on AM60B magnesium alloy. Uniform electroless layer with moderate phosphorus content and also with about 20 μm thickness was successfully applied on the magnesium alloy

Keywords:

Electroless Ni-P plating , Maleic acid , SEM , XRD