In the process of electrochemical metallization, a positive charge is generated on a metal electrode, coated with specially made metal plating gel and connected to an anode output. Upon the impact of the current, metal, contained in the inorganic compound salt of the gel, transits into ionic form and becomes molecularly bound together with the processed surface of the piece, connected to the cathode output and possessing a negative charge.
Example: the gold-plating of a chrome-plated piece
Step 1: REMOVAL OF CHROME LAYER
Gold-plating of chrome-plated badges, pads, inserts, a/m wheels is widely used in the upgrading of cars and motorcycles, and occupies one of the most capacious segments of the gold-plating market. A chrome surface has a barely-soluble inert oxide film, whose adhesion deteriorates during the application of metallic coating. Therefore, the removal of the chrome layer is the first step in the gold-plating of a chrome-plated surface. For this purpose we shall use Universal cleaner. In the course of the removal of the chrome layer, the pad becomes bright yellow. Removal of the chrome layer from a car badge may take 1-2 minutes, whereas the removal of the chrome layer from a chrome-plated a/m wheel may take about an hour. Upon completion of this step, the piece surface should be washed with distilled or de-ionized water.
Step 2: ACTIVATION
After removing the chrome layer, the piece surface will have a barely-noticeable yellowish tinge this is the layer of nickel, which is used as an intermediate sub-layer to enhance the anticorrosion properties of chrome-plated coating. Prior to the implementation of the electrochemical gold metallization process, it is necessary to carry out the activation of the nickel coating. For this purpose we shall use Activator. Activation is used for the purpose of micro etching, removing residual oxides from the piece surface, and improving the adhesiveness of the metallic coating. During the course of activation the pad does not change colour, and the reaction itself is barely noticeable. This step is deemed to be completed after the application of a certain amount of activator to the piece surface, using the pad. After the activation process the surface should be washed with distilled or de-ionized water.
Step 3: GOLD-PLATING
After completion of the activation step we may start the selective electrochemical gold metallization process. For this purpose we shall use Gold-plating gel 24Kt. We shall moisten the pad with gold-plating gel and make slow circular motions over the surface. In the course of this process, under the impact of the current, gold, contained in the inorganic compound salt of the gel, transits into ionic form and is restored to a fine metal on the processed metal surface, forming a poorly-porous under stressed layer, which is molecularly bound to this surface. After the deposition of the gold the coating has an improved surface structure, bright shine, and a level of hardness and durability that is several times higher, in comparison to gold applied using the tank electroplating method.
