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Electroplating = Electrodeposition - the two terms are used interchangeably;
"Electrodeposition is the deposition of a substance on an electrode by the action of electricity (especially by electrolysis)" wolframalpha.com


Some of the hyperlinks in the following text lead to other websites, published articles & general public information;

What is electrodeposition?

From Svante Arrhenius’ (1859-1927) hypothesis, it has emerged that when an electrolyte is dissolved, the molecule dissociates either partially or totally into two or more parts called ions, which have opposite electrical charge. Electrodeposition is a process of using electrical current to reduce metal cations in an electrolytic solution in order to coat a conductive object with a thin adherent layer of metal, thereby modifying the surface properties.

How does it work?
During one common form of electrodeposition, the part to be plated (cathode), and the desired metal which is to be plated onto the part (anode), are immersed in an electrolyte containing dissolved metal salts and other ions which allow proper flow of electricity through the solution. The anode (+) is connected to the positive terminal of a power supply, while the cathode (-) is connected to the negative terminal. An external direct current is then applied commonly by means of a rectifier to the cathode, thereby causing the metal ions in the electrolyte to lose their charge and plate out of the solution and onto the cathode. As current is passed through the circuit, the anode is oxidized to form cations (which have positive charge) and associate with the anions (with negative charge) in solution. The cations are then reduced at the cathode thereby depositing the metal onto the part to be plated. It is analogous to a galvanic cell acting in reverse (ie., an electrolytic cell), since anions must be induced to move to the anode for oxidation, while cations have to be drawn to the cathode for reduction.

Simple Electrodeposition Diagram
Simple Electrodeposition Diagram
Why electroplate?
Electroplating achieves various desirable effects, such as reduced friction, abbrasion & wear resistance, corrosion & electrical resistance, increased heat tolorance, improved aesthetics, and can also be used to increase thickness of undersized parts.

For further introduction regarding plating read Electroplating from the online electrochemistry encyclopedia (Case Western Reserve University).


Some factors to consider which influence electrodeposition;
Solution Concentration - Maintain metal ion and non-metal chemical content at or near optimum levels.
Impurities In Solution - Cleanliness is essentail to successful plating!
Substrate Surface - Influences adhesion and the structure and texture of a deposit.
Current Density - Strongly influences the deposition rate, plating adherence, and plating quality.
Temperature - Changes chemical effectiveness and Influences rate of diffusion.




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