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. Th e 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. Th e 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