Effect of Laser on Abnormal Reduction Process and Properties Evaluation of Electrodeposited Soft Magnetic Fe-Ni Coating

Abstract

Electrodeposition (ECD) process of Fe-Ni coating belongs to abnormal co-deposition according to Brenner’s classification, in which Ni is mainly affected by activation, and Fe is mainly affected by diffusion. In this paper, Fe-Ni coating was prepared by laser-assisted electrodeposition (LECD) technology. The regulation of Fe and Ni contents and coating properties is achieved by using the influence of laser thermal and force effects on the abnormal co-deposition process. The results show that the laser positively shifts the reduction potential and increases the current density. At the laser single-pulse energy is 15 μJ and the laser scanning speed 3000 mm s−1, the Fe content of the coating is the lowest, and the Ni content is the highest, which refines the average grain size and reduces surface roughness. Under these parameters, the coating has a small corrosion current density of 5.8 × 10−7 A cm−2 and a large impedance of 4.3 × 104 Ω·cm2, its coercivity increases by 0.7 Oe, and its saturation magnetic induction intensity declines by 4.7 emu g−1. Compared with the electrodeposited Fe-Ni coating, the corrosion resistance is improved, and the soft magnetic properties is slightly weakened.