Corrosion resistance of Ni–P/SiC and Ni–P composite coatings prepared by magnetic field-enhanced jet electrodeposition

Abstract

To extend the working life of 45# steel, Ni-P and Ni-P/SiC composite coatings were prepared on its surface by magnetic field-enhanced jet electrodeposition. This study investigated the effect of magnetic field on the corrosion resistance of Ni-P and Ni-P/SiC composite coatings prepared by conventional jet electrodeposition. The surface and cross-sectional morphologies, microstructure, and composition of the composite coatings were determined by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD), respectively. The corrosion resistance was studied using a LEXT4100 laser confocal microscope. The introduction of a stable magnetic field was found to improve the surface morphology of the coatings, increase the growth rate, and reduce the agglomeration of nano-SiC (3 g L^-1, 40 nm) particles, thus significantly improving the corrosion resistance of the coatings. The corrosion potential of the Ni-P coating increased from -0.78 V (0 T) to -0.46 V (0.5 T), and the corrosion current density decreased from 9.56 × 10^-6 A dm^-2 (0 T) to 4.31 × 10^-6 A dm^-2 (0.5 T). The corrosion potential of the Ni-P/SiC coating increased from -0.59 V (0 T) to -0.28 V (0.5 T), and the corrosion current density decreased from 6.01 × 10^-6 A dm^-2 (0 T) to 2.90 × 10^-6 A dm^-2 (0.5 T).