Microstructural, surface and electrochemical properties of a novel Ni-B/Ni-W-BN duplex composite coating by co-electrodeposition

作者：Li, Baosong^*; Zhang, Weiwei; Li, Dandan; Huan, Yuxing; Dong, Jia

来源：Applied Surface Science, 2018, 458: 305-318.

DOI：10.1016/j.apsusc.2018.07.100

• Electrodeposition
• Duplex coatings
• Microstructural
• Nanocomposite
• XPS

In this study, a novel Ni-B/Ni-W-BN duplex nanocomposite coating was successfully developed by co-electrodeposition. Their microstructural, surface and electrochemical properties were evaluated and compared to that of monolayer Ni-B, Ni-W, and Ni-W-BN coating by SEM, AFM, EDS, XRD and XPS. The electrochemical behaviors of the coatings were investigated by EIS in 3.5 wt% NaCl aqueous solution. The effects of graphite-like BN nanoparticles on the properties of the duplex coating were discussed. The mechanism of electrochemical codeposition was proposed. Results show that all the coatings are uniform, compact and crack-free. The crystal size of the Ni-B/Ni-W-BN duplex composite coating is smaller compared to monolayer Ni-W-BN coating. The inclusion of BN nanoparticles in Ni-W matrix affect the content of nickel and tungsten of the deposits, increase the hardness and reduce the wear weight loss of the duplex composite coating. As a newly deposited layer with more active sites, the underlayer Ni-B much affects the morphologies of the top layer Ni-W-BN of the duplex coating. The incorporation of graphite-like BN nanoparticles into spherical-like Ni-W matrix increased the surface roughness and decreased the porosity. The Ni-B/Ni-W-BN duplex composite coating exhibited higher corrosion resistance than Ni-W and Ni-W-BN coating. The corrosion resistance was firstly increased and then decreased with the increase of BN. The optimum corrosion resistance could be obtained at 5 gL(-1) BN nanoparticles in bath. However, a higher concentration of BN nanoparticles is detrimental to the properties of the duplex coating.

• 出版日期2018-11-15
• 单位河海大学