Electroplating Basics

Refs. [i] Kanani N (2004) Electroplating basic principles, processes and practice. Elsevier, New York [ii] Newman LS, Newman JH (1979) Electroplating and electroforming for artists and craftsmen, by Lee Scott and Jay Hartley. Crown Publishers, New York... 

Electroplating. Basically in electroplating, a substrate is coated with a metal or its alloy in a plating bath where the substrate is the cathode and the temperature is maintained constant Membranes from a few microns to a few millimeters thick can be deposited by carefully controlling the plating time, temperature, current density and the bath composition. Dense membranes made of palladium and its various alloys such as Pd-Cu have been prepared. Porous palladium-based membranes have also been made by deposition on porous support materials such as glass, ceramics, etc. 

N. Kanani, Electroplating — Basic Principles, Processes and Practice, Elsevier, Oxford (2004) 88. 

N. Kanani, Electroplating basic principles, processes and practice, Elsevier,... 

Although the basic principles of electroplating remain unchanged, the extent of development and variety of application have widened substantially. In this section some notable developments will be cited. 

Cathodic deposition (electrocrystallization) of metals is the basic process in electrometallurgy and electroplating. 

The nickel-chromium plating process includes the steps in which a ferrous base material is electroplated with nickel and chromium. The electroplating operations for plating the two metals are basically oxidation-reduction reactions. Typically, the part to be plated is the cathode, and the plating metal is the anode. 

Several basic principles well known to the electroplating industry are employed in electrolytic recovery expanded cathode surface area, close spacing between cathode and anode, and recirculation of the rinse solution. Electroplaters can design their own units by... 

The two areas specified will require the coverage of a wide range of chemistry. Although the basic principles of electroplating are well understood, and the role of coordination compounds in some plating baths well established, new work and new directions are discernible, particularly in relation to bath additives and their mode of action. 

The basic Brophy and Ingraham technique was studied by several other authors. Bayer and Trivedi " found that the effectiveness of the technique depended more on the nature of the coating than on its thickness, and that retained moisture in the electroplate was essential for effective conversion. They recommended a current density of 21.5 A/m for 5 minutes to produce a coating thickness of 1.25 to 2.5 tjm. Nishimura and co-workers found that the presence of air or water or both in the conversion gas improved the wear life. Table 9.5 compares the properties of the in situ films with those of burnished and sputtered films, and shows superior wear life for the in situ films. Their friction results were curious, in that they found that the initial films which were formed gave low friction in air or nitrogen but not in vacuum. Low friction in vacuum was obtained when the initial product was heated in vacuum to 400°C. 

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