Effects of WS2 on microstructural characteristics and corrosion behavior of Ni-W and Ni–W/CrN composite coating electrodeposited continuously from a dilute citrate-based electrolyte

Ni–W/WS 2 and Ni–W/CrN–WS 2 composite coatings were fabricated via continuous electrodeposition from a dilute citrate-based electrolyte containing varying concentrations of WS 2 nanoparticles. The influences of WS 2 content on the surface morphology, elemental composition, phase structure, surface roughness, chemical valence states and corrosion behavior were systematically explored. The results demonstrate that the incorporation of WS 2 nanoparticles refines the grain structure, reduces surface roughness, suppresses particle agglomeration, and promotes the formation of a denser and more homogeneous microstructure. When the concentration of WS 2 exceeds 8 g L −1 , WS 2 particles induce agglomeration and increase internal defects within the coating, thereby impairing its structural compactness and corrosion resistance. XRD and XPS analyses confirm that CrN and WS 2 are successfully co-deposited into Ni–W coating without changing the primary chemical states of Ni, W, Cr, N and S. AFM measurements reveal that 6 g L −1 WS 2 effectively reduces the surface roughness, which is beneficial to the improvement of tribological properties. EIS results demonstrate that 1 g·L −1 WS 2 significantly enhances the anti-corrosion property of Ni–W/WS 2 deposit with the highest R p 123.78 kΩ·cm 2 ( R c 64.47 plus R ct 59.21 kΩ·cm 2 ), forming a reliable physical barrier against corrosive media. In contrast, for the dual-particle synergistic strengthening phase of CrN–WS 2 , the anti-corrosion property of Ni–W/CrN–WS 2 coating is gradually improved as the addition amount of WS 2 increases, reaching the optimal performance at 8 g·L −1 . The corrosion resistance of the Ni–W/CrN–WS 2 coating improves as the WS₂ concentration rises, peaking when the WS₂ concentration is 8 g·L⁻¹ . The synergistic effect of CrN ceramic particles and WS 2 solid lubricant optimizes the microstructure and anti-corrosion performance of Ni–W composite coatings. These composite coatings demonstrate significant potential as corrosion-protective coatings in aggressive service environments, including marine environment and oil–gas pipeline systems.