EFFECT OF BATH pH ON ELECTROLESS Ni–P COATING DEPOSITED ON OPEN-CELL ALUMINUM FOAMS
Abstract
Different electroless Ni–P coatings were deposited on open-cell aluminum foams at various bath pH. The effect of bath pH on the morphology, structure, components, phases and corrosion resistance of the Ni–P coating was studied by scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), immersion test and electrochemical polarization measurement, respectively. The experimental results show that the bath pH not only changed the reactivity of the bath, but also had a influence on the microstructure and anticorrosive property of electroless Ni–P coating. The high pH bath raises the thickness of Ni–P coating but decreases the content of phosphorus element in the Ni–P coating. The corrosion resistance of the coated aluminum foams increases when the bath pH rises.
