Effect of electroless Ni-P coatings containing nano additives on surface topography of magnesium alloy

Abstract

In order to improve the wear and corrosion behavior for the alloys, coating is found as the most suitable method. Mg base alloys have a wide range of industrial application. These alloys shows a high specific strength but poor wear and corrosion resistance. An ordinary coating of Cu, Ni & Zn etc. provide a physical barrier against the wear rate and corrosion attack of magnesium substrate. In the present investigation, Ni-P plating was done on AZ91 composite by immersing samples into Nickel sulphate bath in presence of surfactants. The mechanism of Ni-P deposits was studied by using SEM. Ni-P coating was coated uniformly in the presence of surfactants. Effect of surfactant and Effect of Nano-additives Al2O3, ZnO, and SiO with different quantities were studied. 0.5 g/l Nano Al2O3 additive enhanced the deposition of Ni-P on AZ91 magnesium composite and the same results have been observed in case of SiO addition. Influence of ZnO was also observed. So is very clear that Ni-P coating is very effective to reduce the corrosion and increase the wear behaviour if it is used along with Nano additive and the surfactants.