Optimization of Electroless Ni-P deposition on AZ31Magnesium alloy

In this study, the formation ElectrolessNi-P coating on AZ31 Mg alloy by commercial bath SLOTONIP70 wasinvestigated. In this regard bath condition was determined and the effect of surface preparation parameter on properties of coating was studied. The time and required amount of acid hydrofluoric was introduced.After coating in optimum conditions, X-Ray analysis, Scanning Electron Microscopy (SEM) and Energy Dispersive spectroscope (EDS) were used to characterize the coatings.The result showed that Sand blast process before coating was necessary stage to inhibit crack formation in the coatings. The optimum condition for coating was 35wt% HF, pH 6/4 and the temperature 80°C. In these conditions the crystallized cauliflower-like structurecoating content about 3-4wt% of phosphorus was obtained.