Jet electrodeposition multilayer nickel on the surface of sintered NdFeB and corrosion behaviours

Abstract

Sintered neodymium (NdFeB) magnet material is highly vulnerable to corrosion. To solve this problem, three kinds of structures (dark nickel, bright nickel, and multilayered nickel) were produced efficiently and quickly by using jet electrodeposition technology. The structure and microstructure of the coatings were analysed by X-ray diffraction and field-emission scanning electron microscopy, respectively. The corrosion resistance of the samples was evaluated by potentiodynamic polarisation (Tafel). By comparing the corrosion behaviours of different structures, we found that the corrosion resistance of multilayered structure nickel coating was much higher than that of single layered nickel and the surface quality was significantly improved compared with dark nickel, which can better protect the NdFeB material.

Electrochemical jet manufacturing technology: From fundamentals to application

“…In addition to alloys, lamellae coatings can be fabricated by jet electrodeposition by alternating the parameters [168], or the electrolyte composition interacting with the surface at a given time. For example Shen et al [169] created Cu-Ni multilayer coatings by jet electrodeposition using two opposed nozzles drawing from discrete electrolyte tanks using a rotating workpiece (Fig.…”

Properties of Jet electrodeposition Nickel Coating on TC4 Alloy Prepared by Selective Laser Melting

“…On the one hand, this is caused by the current density being too high and the deposition rate being too fast. On the other hand, nickel ions in the vicinity of the cathode are rapidly consumed, and a serious shortage of nickel ions causes hydrogen ions in the solution to be reduced, thereby increasing plating defects [27].…”

The microstructure and protective properties of electroplating zinc films on NdFeB from a chloride-free nonaqueous bath

“…[12][13][14] Metal coatings, such as Ni, [15][16][17][18] Ni-P, 19,20 Ni-Cu, 21,22 Zn, [23][24][25][26] are the most popular choices in the industry. So far, aqueous electroplating is still the most widely used method of metal coating deposition, [27][28][29][30] although physical vapor deposition, [31][32][33] chemical vapor deposition, 4 thermal spraying, 34 and other technologies have also developed. Unfortunately, NdFeB is prone to corrosion during the aqueous electroplating process due to exposure to the electrolytic bath solution.…”