A study on steady-state magnetic field in the surface morphology and internal stress of electrodeposited amorphous Ni-Fe-P alloy based on laser irradiation

Abstract

The laser thermal effect effectively reduces the internal stress of Ni-Fe-P coating, but it still exists in the form of tensile stress. In this paper, a steady-state magnetic field is introduced into laser-assisted electrodeposition (LECD). Whether the magnetohydrodynamic (MHD), magnetic, and magnetization effect can alleviate the residual tensile stress of amorphous Ni-Fe-P coating was discussed. The results indicate that magnetic field impacts the formation of particle clusters and the reduction of the number of micro-cracks. When the magnetic field strength is 15 mT, the internal stress exists in compressive stress (150 MPa). When the magnetic field strength is 25 mT, the surface micro-cracks formed directionality. Based on LECD, the influence of magnetic field on ECD rate is not significant, while the Fe content increases because of the MHD effect. In addition, when a magnetic field is added, the amorphous structure does not change. When the magnetic field intensity is 15 mT, the diffraction peak of XRD is broader and smoother, indicating that the size of the crystal nucleus is smaller. Moreover, compared with LECD, magnetic field and laser assisted ECD (MLECD) improves corrosion resistance, but decreases wear resistance.