Study on wear resistance and corrosion resistance of zirconium phenylphosphonate reinforced Ni–W composite coating

Abstract

In this work, with the help of pulsed electrodeposition technology, Ni–W/ZrPP composite coatings on carbon steel surfaces were fabricated. The enhancing effects of inorganic layered alpha-zirconium phosphate (αZrP) and organic zirconium phenylphosphonate (ZrPP) on the surface morphology, microhardness, wear resistance and corrosion resistance of Ni–W coatings were also investigated. The result shows, Ni–W/ZrPP composite coating exhibits the most complete and dense surface morphology without any pinholes and generation of microcracks. Furthermore, the embedding of ZrPP also maximizes the wear and corrosion resistance of the Ni–W coating. This can be reflected by the fact that the Ni–W/ZrPP composite coating has the shallowest and narrowest wear section and the lowest average friction coefficient (0.312). In 3.5 wt.%NaCl solution, the Ni–W/ZrPP composite coating has the highest corrosion potential (Ecorr = −0.28 V) and the lowest corrosion current density (icorr = 2.3 μA cm−2), which show the best corrosion resistance. Relevant mechanistic studies have proven that embedding ZrPP with larger interlayer spacing in the coating is beneficial to promote the interlayer slip of 2D materials and to from frictional transfer films. The hydrophobic group and lamellar structure at the end of ZrPP are also contributors to build a physical barrier and prevent corrosive media from entering the coating.