Preparation and Corrosion Resistance of Electroless Ni-P Coating on Open-Cell Aluminum Foams

The electroless Ni-P coatings were deposited on open-cell aluminum foams substrate by using hypophosphite as a reducing agent. Ni-strike was developed as a pre-treatment for Ni-P coatings to interlock between the substrate and coatings. Thereby, it improves the corrosion resistance of Ni-P coatings on open-cell aluminum foams substrate. The surface morphology, structure and phases of the Ni-P coatings were characterized by SEM-EDS and XRD. The corrosion behaviours of the coated and uncoated aluminum foams were evaluated by immersion test and electrochemical polarization measurement. The experimental results show that the Ni-P coatings cover the entire surface with a thickness of similar to 25 mu m. The coated aluminum foams have good corrosion potential and enhanced corrosion resistance compared with as-received aluminum foams.