Effect of parallel magnetic field on growth and properties of jet electrodeposited Ni-Co-SiC composite coatings

Abstract

Ni-Co alloy and composite coatings were fabricated by a parallel magnetic field-assisted jet electrodeposition (PMAJE), and the effect of nano SiC particles on the properties of Ni-Co alloy coating was studied. Crystal structure, micromorphology and 3D profile, microhardness, adhesion and corrosion resistance of the Ni-Co alloy and composite coatings were studied respectively. The deposition mechanism of Ni-Co alloy and composite coatings in PMAJE was analyzed. It was found that the parallel magnetic field (PM) significantly affected the surface morphology and flatness of Ni-Co alloy and composite coatings in jet electrodeposition. The microprotrusions of Ni-Co alloy and composite coating gradually increased with the magnetic flux density. PM refined the grain growth of Ni-Co alloy and composite coating when the magnetic flux density was 50 mT. Compared with jet electrodeposition, the Ni-Co-SiC composite coating exhibited a high mechanical properties and corrosion resistance in PMAJE. The microhardness of Ni-Co-SiC composite coating was 582.4HV, the adhesion was 27.2 N, the corrosion current density of Ni-Co-SiC composite coating was as low as 5.824 μA·cm−2 and the polarization resistance reached 6471 Ω·cm2, which was better than that of jet electrodeposition.