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A Brief Overview of the Electroplating Process There are several methods of finishing a surface, among them powder coating, painting and electroplating. Electro-plating is the process of plating a surface with metal ions. Electric current is passed through a solution containing the metal ions with the surface to be coated as the electrode. Electro-plating leads to the formation of a thin layer of the coating material. You get to choose the material to plate with, meaning you can plate to get the desired properties. You can plate to get such properties as wear- and abrasion-resistance, corrosion resistance, lubricity, and aesthetic qualities. The first process in electro-plating is cleaning the surface. This is important because even a molecular layer of dirt or oil can prevent proper adhesion. You should follow the ASTM B322 standard when cleaning the surface. The most commonly used cleaning processes are acid treatment solvent cleaning, hot alkaline detergent cleaning, and electro-cleaning. You then do an industrial cleanliness test, the most common being waterbreak test. The next process is the deposition of ‘flash’ or ‘strike’. Striking is the deposition of a thin plate that has high adherence. The deposition is about 0.1 micrometer thick. The flash is the foundation on which the plating is based. High current density in a bath of low ion concentration is used for this. The process has to be slow for it to be effective. Electro-plating takes place through electrodeposition. DC (direct current) is applied from a battery or a rectifier to an anode and a cathode. These are immersed in a plating bath with the ions of the metal to be deposited. This leads to a chemical reaction resulting in electrodeposition. It is also possible to do electro-less deposition whereby only one electrode is used and there is no external power supply. A reducing agent is however, needed in the plating bath. Yet another electroplating method is brush electroplating. This is the process of plating of the surface with a brush that is saturated with the plating solution. The brush used is usually a stainless steel body that is wrapped in cloth. It holds the plating solution while preventing direct contact with the surface that is being plated. The process involves the use of low voltage DC power, with the surface being plated being connected to the –ve power source. The brush is moved continuously over the surface. This method is popular over the traditional tank plating since it is portable. Reviewed websites: http://www.metalfinishing.com http://www.cirelectroplating.co.uk/ http://www.electroplating.co.uk/ http://www.electroplating.com/

Electroplating  

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