Electroless nickel alloys are applied because of their useful physical and mechanical properties. Black electroplating nickel coatings are used in optical instruments, absorbing material, decorative coatings and aerospace industries. They are specified due to their stability against sunlight exposure and electrical conductivity. Electroless plating of nickel phosphorous and nickel tungsten phosphorous on aluminium substrate were discussed. Blacking of both nickel phosphorous and nickel tungsten phosphorous by electroplating were investigated by the reflectance percent and the absorption percent for black nickel coating from the Ultra-Violet Device (UV) at different wave lengths ranging from (230-700nm) as the reflectance = (1- absorption) and by X-ray photoelectron spectroscopy (XPS). The influence of blackening was discussed by comparing it with original deposits. All coats were investigated by X-ray diffraction, scanning electron microscope (SEM) and energy dispersive X-ray analyses (EDX) Optical property and thermal stability. Corrosion resistance of both nickel phosphorous, nickel tungsten phosphorous and the black coats were studied by potentiodynamic polarization.
