An alkaline electroless treatment that forms a low-phosphorus Ni-P coating directly on magnesium was performed as a chromate-free pretreatment that provides a suitable base for deposition of a high-phosphorus corrosion resistant electroless nickel coating. The use of a slightly acidic bath, limited the substrate corrosion during the deposition process and allowed the subsequently deposition of high-phosphorus coating which enhances the corrosion and wear resistance of the commercially purity magnesium (99.9%) and AZ31B magnesium alloy. The morphology and composition of coatings were investigated by means of scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis and Rutherford backscattering spectrometry (RBS). Corrosion behavior was assessed using hydrogen evolution and potentiodynamic polarization measurements. The corrosion products were characterized by means of Raman microscopy.
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