Enhanced mechanical and corrosion protection properties of pulse electrodeposited NiP-ZrO2 nanocomposite coatings

Abstract

Pulse electrodeposition is a technique of particular interest, which offers promising advantages such as ease of processing, compositional control, uniformity in structure, and grain refinement. In the present study, NiP-ZrO2 nanocomposite coatings containing various concentrations of ZrO2 nanoparticles (ZONPs) were deposited on low alloy steel (30CrMnSi) through pulse electrodeposition technique. The ZONPs in concentration of 0.0, 0.25, 0.50, 0.75, and 1.0 g/L were added in the electrolyte bath to obtain NiP-ZrO2 nanocomposite coatings. Furthermore, to elucidate the role of ZONPs in the NiP matrix, the structural, morphological, mechanical, and electrochemical properties of NiP-ZrO2 nanocomposite coatings were studied thoroughly. FESEM and EDX results reveal the successful incorporation of ZONPs into the NiP matrix. XRD and XPS analysis confirm the formation of a pure phase NiP structure without any noticeable defects. A considerable improvement in the mechanical response was observed with an increasing amount of ZONPs, reaching to highest values (hardness 6.7 GPa, modulus of elasticity 21.72 GPa) for NiP-1.0 ZrO2 coating composition. Similarly, the electrochemical results show a gradual increase in corrosion protection behavior of the NiP-ZrO2 coatings with increasing ZONP concentration, reaching an eventual value ~5.8 kΩ cm−2 at NiP-1.0 ZrO2 coating composition, which is six times greater than the pure NiP coatings. These improvements in the mechanical and electrochemical response of NiP-ZrO2 nanocomposite coatings highlight their suitability for applications such as oil and gas pipelines.