Impact of Magnetic Field Direction on Performance and Structure of Ni-Co-SiC Coatings Fabricated via Magnetic-Field-Induced Electrodeposition

This study reports the synthesis of Ni-Co-SiC coatings onto Q235A steel substrates through magnetic-field-induced electrodeposition to improve the surface performances of the machine parts. The microstructure, topology, roughness, corrosion, and wear resistances of the coatings were investigated through X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), hardness testing, electrochemical analysis, and friction wear testing, respectively. The Ni-Co-SiC coating deposited at 0.4 T (MS1) with a perpendicular magnetic direction showed the maximum SiC content and NiCo grain size (86.5 nm). The surface topology was also fine, dense, and smooth. In addition to that, the images obtained from the AFM characterization showed that the surface roughness of the MS1 coating was 76 nm, which was significantly lower compared to the roughness observed in Ni-Co-SiC coatings fabricated under the magnetic induction of 0 T (MS0) and magnetic field applied in a parallel direction to 0.4 T (MS2). The XRD results revealed that the preferential growth direction of the NiCo grains was changed from the (200) crystal plane to the (111) plane with the introduction of a perpendicular magnetic field. Moreover, MS2, MS1, and MS0 had thickness values of 25.3, 26.7, and 26.3 μm, respectively. Among all the coatings, MS1 showed the lowest friction coefficient and the highest hardness value (914.8 HV), suggesting enhanced wear resistance. Moreover, the MS1 coating revealed a maximum corrosion potential of −257 mV, and the lowest corrosion current of 0.487 μA/cm², suggesting its improved corrosion resistance.