Electrodeposition electroplating

Elemental copper is the least easily oxidized of the first-row transition metals. This largely accounts for the extensive use of copper electrodeposition for both industrial applications and analytical purposes. Since the electrochemistry of elemental copper, including electrodeposition, electroplating, and electrowinning, was treated extensively in the previous edition of this encyclopedia [1] and detailed descriptions are to be found elsewhere [2-4], it is not covered in this treatise. 

Electrodeposition, Electroplating, and Electrorefining. When an electric current passes through a solution (for instance, silver nitrate), the precipitation of a material (silver) at an electrode (the cathode)... 

Coating methods are electrodeposition, electroplating, physical vapor deposition (PVD), chemical vapor deposition, sputtering, spraying, and nitriding. 

Aqueous Electrodeposition. The theory of electro deposition is well known (see Electroplating). Of the numerous metals used in electro deposition, only 10 have been reduced to large-scale commercial practice. The most commonly plated metals are chromium, nickel, copper, zinc, rhodium, silver, cadmium, tin, and gold, followed by the less frequendy plated metals iron, cesium, platinum, and palladium, and the infrequendy plated metals indium, mthenium, and rhenium. Of these, only platinum, rhodium, iddium, and rhenium are refractory. 

Electrodeposition of Metals. Citric acid and its salts are used as sequestrants to control deposition rates in both electroplating and electroless plating of metals (153—171). The addition of citric acid to an electroless nickel plating bath results in a smooth, hard, nonporous metal finish. 

Practices for preparation of and electroplating on Chromium (Electrodeposits) on Chromium Copper and Copper-Base Mllojs Iron Castings Eead and EeadMllojs Magnesium and Magnesium Mllojs Molybdenum and Molybdenum Mlloys MickelMlloys... 

Electroplating—the process of electrodeposition onto a metallic substrate of a thin adherent layer of a metal or alloy having desirable chemical, physical and/or mechanical properties. 

The use of electrodeposited metals to protect corrodible basis metals from their service environments has been well established for many years and accounts for by far the larger part of the activities of the plating industry. There are many reasons for using an electroplated metal finish in preference to an organic finish or to making the articles concerned from inherently corrosion-resistant materials. 

It will be seen that the design of articles to be electroplated can have a considerable effect on the corrosion resistance of the electrodeposited coating. The chief effects are the result of variations in deposit thickness, but also important are features which can influence the adhesion, porosity and physical properties of the deposit. Good design will also avoid features of the plated article capable of trapping liquids or solid contaminants which might cause more rapid corrosion. 

Fig. 12.12 An electrodeposit showing unusually high compressive stress. A ISO x ISO mm copper sheet was insulated with lacquer on one side and electroplated with Sn-3S Ni alloy. The high compressive stress has caused the sheet, originally flat, to coil in the manner shown, with...

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