Structure analysis of electroless Ni-P-Al2O3 nanocomposite coatings

Abstract

Abstract. Ni-P-Al 2 O 3 nano-composite coatings were successfully fabricated on a P20 plastic die steel surface by electroless plating process containing sulfate nickel, sodium hypophosphate and suspended Al 2 O 3 nanoparticles. The pH value and temperature of the electroless bath were 4.5 and 87ºC, respectively. The coating was characterized for its microstructure, morphology, microhardness and corrosion resistance. Surface analysis using a field emission scanning electron microscopy (FESEM) showed that the dispersible Al 2 O 3 nanoparticles were co-deposited with electroless Ni-P coating onto substrates, the incorporation in Ni-P matrix of Al 2 O 3 nanoparticles increases the nodularity of composite coatings. The crystallinity, phases and element distribution of coating were analyzed by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). It was evident that the X-ray diffraction pattern of the composite coating is similar to that of nanoparticle free coating, both coatings have amorphous structures.