Exploring the dual effect of sodium lignosulfonate-modified LDH treatment and heat processing on elevating corrosion and wear resistance of Ni-W composite coatings

Abstract

The exploration of Ni-W composite coatings with high corrosion and wear resistance is highly important for engineering applications. In this study, LDH-SLS composite nanomaterials were synthesized via hydrothermal synthesis, and Ni-W/SLS composite coatings with excellent wear and corrosion resistance were prepared via pulsed electrodeposition combined with heat treatment. The successful synthesis of LDH-SLS was confirmed by TEM, EDS, FTIR, XPS and XRD analyses. Furthermore, multipoint BET specific surface area analyses demonstrated that pore size and the specific surface area of the LDH materials were enhanced by SLS. Corrosion studies showed that the Ni-W/SLS coatings with the addition of the LDH-SLS nanomaterial had higher impedance compared to the Ni-W coatings. And the Ni-W/SLS coating can show better corrosion resistance after heat treatment at 400°C with an impedance of 2.98 ×104 Ω·cm2, which is 502.2 % higher than that of the Ni-W coating, and a corrosion current of 7.2399 ×10−7 A/cm2, which is two orders of magnitude lower than that of the Ni-W coating. Comparative analyses of coating microhardness, friction curves and average friction coefficients show that heat treatment at appropriate temperatures can significantly improve the wear resistance of Ni-W coatings. The Ni-W/SLS coatings heat treated at 400°C showed the most desirable wear resistance. This study presents a new method for producing Ni-W coatings with high corrosion and wear resistance.