Enhancement of surface properties with influence of bath pH on electroless Ni-P-ZnO/Al2O3 nano-composite deposits for defence applications

The focus of this paper is to experimentally investigate the effect of ENi-P-ZnO/Al2O3 composite deposition on corrosion and wear resistance, surface morphology, crystallographic structure, microhardness, surface roughness (Ra) and wettability, on mild steel specimen, by maintaining bath pH at 5, 7 and 9. On investigation, it is revealed that incorporation of ZnO and Al2O3 sharply improves the corrosion resistance, microhardness, coefficient of friction, wear rate, surface roughness and morphology of the as-deposited samples as against nondeposited mild steel specimen. Incorporation of ZnO nanoparticles results in 96% reduction in corrosion rate (7.92 mmpy) as against the without deposited mild steel specimen (180 mmpy) and incorporation of Al2O3 nanoparticles results in 184% increase in microhardness (625 Hv) as against the without deposited mild steel specimen (220 Hv), under optimum operating conditions of bath pH 7 and pH 9 respectively, thereby enhancing applications in various defence fields like marine and aviation. (C) 2017 Elsevier B.V. All rights reserved.