Effect of nanoadditives with surfactant on the surface characteristics of electroless nickel coating on magnesium-based composites reinforced with MWCNT

Abstract

An experimental investigation has been carried out on optimizing process parameters of electroless nickel-phosphorous coatings on magnesium composite reinforced with carbon nanotube. A comprehensive experimental study of electroless Ni-P coatings on magnesium composite reinforced with multiwalled carbon nanotube under specific coating conditions was performed. The electroless coating bath consists of nickel sulphate (26 g/L), sodium hypo-phosphite (30 g/L) as reducing agent, sodium acetate (16 g/L) as stabilizer, and ammonium hydrogen difluoride (8 g/L) as the complexing agent. The surfactant SLS was added in the solution for better wetting and spreading of coating on substrate. The stabilizer thiourea (1 ppm) was added in the bath to prevent decomposition of bath. Different nanoadditives such as ZnO, Al2O3, SiO with various concentrations were used in the bath and their influence on coating process characteristics were studied The nano additives such as ZnO, Al 2O3, SiO were added at concentrations of 0.1%, 0.5%, 1%, and 2% in the EN bath. The output parameters such as surface roughness, microhardness, specific wear rate, and surface morphology were measured. Surface morphology was studied using scanning electron microscope. The results showed that the proposed method resulted in significant improvement on the quality of the coatings produced. © 2013 Ranganathan Dhinakaran et al.