Electroless Ni-P-(nano-MoS2) composite coatings and their corrosion properties

• Published in: Surface engineering Vol. 25; no. 5; pp. 361 - 366
• Main Authors: Hu, X. G., Cai, W. J., Xu, Y. F., Wan, J. C., Sun, X. J.
• Format: Journal Article
• Language: English
• Published: London, England Taylor & Francis 01.07.2009; SAGE Publications
• Subjects: COMPOSITE COATING; CORROSION; ELECTROLESS PLATING; NANO-MOS2; CORROSION; NANO-MOS2; COMPOSITE COATING; ELECTROLESS PLATING
• ISSN: 0267-0844; 1743-2944
• DOI: 10.1179/174329408X282532

Ni-P coatings were co-deposited with MoS 2 nanoparticles on medium carbon steel substrate by electroless plating. The effects of incorporation of MoS 2 nanoparticles into the Ni-P coating on the morphology of the coating surface and corrosion properties were investigated. X-ray diffraction pattern and X-ray photoelectron spectroscopy spectra showed that the MoS 2 nanoparticles were covered in the nickel phosphor matrix. Corrosion tests were conducted in aqueous 10 wt-%HCl, 10 wt-%NaOH and 3·5 wt-%NaCl using a weight loss method, and in aqueous 3·5 wt-%NaCl by electrochemical measurement for bare substrate, Ni-P coating and Ni-P-(nano-MoS 2 ) composite coating, respectively. The experimental results showed that corrosion resistance of the coating containing MoS 2 was slightly lower than that of the coating without MoS 2 . The corrosion rate of Ni-P-(nano-MoS 2 ) composite coating in HCl aqueous solution was found to be increased owing to the corrosion microcells and high porosity and rougher surface. Ni-P- (nano-MoS 2 ) composite coating, however, exhibited significantly enhanced corrosion resistance in both aqueous NaOH and NaCl solutions compared with substrate. The corrosion mechanism of the composite coatings was also discussed.