Anticorrosion Effect of Silicon Nitride and Zirconium Diboride Composite on Ni–P– Zn Electroless Deposition on Mild Steel

Abstract

Electroless nicked-based deposition on mild steel surface from a nickel–zinc phosphate bath with NiSO4·6H2O, ZnSO4·7H2O, and NaH2PO2·H2O salt in the presence of silicon nitrides and zirconium diboride as additives at a constant time was studied. The structural evolution of electroless deposited mild steel surface was characterized for crystal change formation using a scanning electron microscope (SEM) and elemental quantification done using energydispersive spectroscopy (EDS). The electrochemical corrosion analysis of the deposited mild steel with and without composite additives was analyzed using linear polarization resistance and open circuit potential in both H2SO4 and NaCl solution. From the results, significant presence and the effect of wt% of additives were noticeable on the electroless mild steel surface. Ni–P–Zn in the presence of 10ZrBr2 and 10Si3N4 actively provide an induced weight gain of 0.0974 g and 0.0973 g, respectively. A correspondent, 0.034 g/m2 coating per unit area of zirconium diboride additives, was obtained against 0.030 g/m2 for silicon nitrides. The structural evolution shows proper homogeneous crystal formation and stable packed additive concentrated at the lattices with EDS showing the presence of induced peak. From the corrosion assessment result, electroless deposited mild steel with Ni–P–Zn–10ZrBr2 and Ni–P–Zn– 10Si3N4 with optimum particle concentration shows better corrosion resistance performance with a corrosion rate of 0.5048 mm/year, and 5.1347 mm/year, as against the unadditive deposition with 11.393 mm/year in NaCl solution