Coatings electrolytic nickel

With hydrometallurgical processes, the presence of NiCd or NiMH batteries requires an additional stage in order to isolate the cadmimn, in nickel-cadmium batteries, and the nickel found in certain batteries at a content of less than 0.1% and in the form of nickel steel or an electrolytic nickel coating. 

In contrast to electrolytic nickel coating, electroless nickel coating, is deposited without any current as the name indicates. The metal is formed by the reduction of nickel ions in solution by a reducing agent. Sodium hypophosphite is used as a reducing agent. The following is the mechanism of reduction. 

Nickel-terne-coated steel includes an electrolytic flash coating of nickel (1-1.5 g/m ) underneath a conventional lead-tin coating for enhanced corrosion resistance. Applications are similar to the conventional lead-tin alloy coatings described previously. 

Heavy electrolytic nickel provided there are no defects in the coating... 

Cold-rolled sheet steel electrolytically nickel flash-plated and then coated on both sides with a lead-tin alloy by a continuous hot-dip process. Corrosion resistance is superior to standard long terne. 

Electroless Electrolytic Plating. In electroless or autocatalytic plating, no external voltage/current source is required (21). The voltage/current is suppHed by the chemical reduction of an agent at the deposit surface. The reduction reaction must be catalyzed, and often boron or phosphoms is used as the catalyst. Materials that are commonly deposited by electroless plating (qv) are Ni, Cu, Au, Pd, Pt, Ag, Co, and Ni—Fe (permalloy). In order to initiate the electroless deposition process, a catalyst must be present on the surface. A common catalyst for electroless nickel is tin. Often an accelerator is needed to remove the protective coat on the catalysis and start the reaction. 

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