| There is a large gap in the present situation of button cell between our country and foreign country, one of a important reason is that the shell material is much worse than overseas’. Now, the production of high level shell material uses electroplate, and stainless steel deposit nickel in 430 mirror surface, which have poor corrosion property and are easily to scratch, making the shells can not meet requirements of advanced button cells. At the same time, advanced button cells need to lettering logo and cell parameters, so the shell can not be too rough, otherwise the logo is blurry. In this paper, the nickel coated mirror stainless steel substrate with a roughness of less than 0.08 μm have been studied to replace the traditional nickel coated stainless steel to solve the problems of lettering and anti-corrosion. The construct of clad layer adopts the thin film structure of multilayer nickels, and the combination way of direct current, pulse and eject in the writing. By testing the combination, anti-corrosion, and electric conductivity, we look for the best technological parameter and offer basis data and theory direction for the exist of industrialization. The work and results are following:(1) To enhance the combination between the mirror stainless steel substrate and the nickel and the anti-corrosion, the coating structure is designed with dark nickel layer at the bottom. The middle layer of film is semi-bright nickel layer. the surface layer of film is all-optical nickel layer in structures of different size nickel thin film.Each material of Thickness is controllable. Designed a multi-layer structure of nickel films overlap each other, and tested each thin nickel corrosion potential, from the inside and the table, gradually increased corrosion resistance.(2) The dark nickel layer, semi-bright nickel layer and all-optical nickel layer were successfully plated on 430 nickel coated mirror stainless steel by combination way of direct current, pulse and eject in the writing. use of SEM, XRD, AFM and other test methods, the multi-layer film structure were characterized and analyzed nickel microstructure. The results show that the grain size of the smallest surface nickel film, corrosion strongest, the most important reason is the different additives;(3) By hundred cells and thermal shock method, 430 stainless steel with nickel-sided adhesion testing and analysis. By hundred cells and thermal shock method, 430 stainless steel with nickel-sided adhesion testing and analysis. The results show that: The key factors affecting the coating and substrate binding is a pre-nickel plating process, and when the pre-nickel plating current density ≥0.5A /dm2, time ≥6s, in order to ensure good adhesion; Tafel curve by extrapolation and neutral salt spray test for corrosion test methods under different process 430 stainless steel mirror-sided nickel coated multilayer materials were characterized. The results show that: pH on the corrosion resistance of the material can affect the most, the worse by poor corrosion resistance optimum at pH 4.3.In summary, the contracture design of Ni thin film coating with multilayer improved the comprehensive character of density and binding force for the material.Then it enhanced its general corrosion resistance ability. Particularly, the introduce of pulse jet plating greatly boost the limiting current density of catelectrode and it will be very beneficial to the industrialization of production. |
