Investigation of the Wear and Corrosion Resistance of Electroless Ni-P/Ni-B Coating Reinforced with Ceria Sol

Introduction and Objectives: Wear and corrosion are among the primary challenges that reduce the service life and performance of industrial components. In this study, a sol-enhanced method is employed to incorporate ceria into electroless Ni-P/Ni-B coatings to improve mechanical, tribological, and corrosion properties.Materials and Methods: A uniform distribution of ceria nanoparticles was achieved by introducing ceria sol derived from an alkoxide precursor into the Ni-B electroless bath. Characterization was performed by XRD and FE-SEM, DLS, potentiodynamic polarization test, and pin-on-disk wear tests.Results: The results showed that the use of ceria sol improved the uniformity of the distribution of reinforcing particles and formed a relatively dense Ni-B coating with good surface quality and no real surface cracks. The surface features were mainly related to the boundaries of cauliflower nodules. The polarization curve indicates a more stable with slower rate of corrosion for the CeO2-containing coating compared to the substrate, due to the formation of a protective layer and increased surface chemical stability. Using the Ni-P/Ni-B-CeO2 coating on the aluminum substrate resulted in a 21% reduction in the friction coefficient and a 70% reduction in the specific wear rate compared to the substrate.Conclusion: Using sol of ceria in Ni-B coatings, due to the prevention of particle accumulation in the coating, led to a significant increase in corrosion resistance, reduced friction coefficient, and improved wear resistance of the coating.