Application of Co–Ni–P Coating on Grain-Oriented Electrical Steel

Abstract

An electroless plating of Co-Ni-P was applied to a grain-oriented electrical steel substrate resulting in a power loss improvement of approximately 9-11 %. The mean thickness of the coating was found to be 2.15±0.15 µm from Environmental Scanning Electron Microscope (ESEM) images. Shifts of the magnetostriction stress sensitivity curves showed that stress was acting on the substrate corroborated by a shift in X-ray Diffraction (XRD) peaks and narrowing of the domains after the samples were coated. The magnetic property measurement system (MPMS) results confirmed the magnetic nature of the coating and XRD results showed peaks of α-Iron in uncoated sample, α-Iron-Cobalt and α-Iron in Co-Ni-P coated sample. The Talysurf profilometer showed a decrease in surface roughness (Ra) values after coating the sample which reduced the hysteresis loss.

Repair of soft magnetic properties of wasted silicon steel and Co7Fe3 alloy deposition mechanism

“…Pornthep Chivavibul et al 8 proposed to electrodeposit Ni–Co–P coating on the surface of silicon steel and studied the effect of different thicknesses of the coating on the hysteresis loss of silicon steel, and it was found that Ni–Co–P coating reduced the hysteresis loss by 4%; however, the effect of the alloy on other soft magnetic properties and corrosion resistance was not reported. Vishu Goel et al 9 coated Co–Ni–P on the surface of the oriented silicon steel and reduced the hysteresis loss by approximately 9% and noted that depositing cobalt-based alloys on the surface of silicon steel helps enhance the soft magnetic properties and reduce the hysteresis loss. Ferromagnetic transition metals, such as Fe, Co, and Ni show the saturation magnetization of 251, 177, and 54.39 emu g −1 , 6 respectively, thus Co–Fe alloys can form coatings with the highest saturation magnetization strength.…”