In addition to pure electroplating, a number of similar processes are also applied in the plating technology, including, for example, the coating without using external current, a number of dipping methods and the related pre-treatment processes. These coatings meet a variety of important technical and decorative functions and increase the attractiveness, functionality, safety and service life of a product.
Aspects such as conductivity or solderability, wear or corrosion resistance, contact behavior and an even distribution of layers as well as a reliable quality of the surfaces are essential. Products having electroplated surfaces are applied in a variety of areas of the industry and everyday life.
Electroplating is the process of depositing metal on a workpiece using direct current. In this process, the workpiece is dipped into an aqueous solution of the corresponding metal salt. The workpiece is connected to the negative pole of a current source, thus becoming a negative electrode (cathode). The metal ions deposited on the cathode are fed back to the solution by using a counter electrode (anode) made of the same metal as contained in the solution and connecting this anode to the positive pole of the current source. As a result, the metal at the anode is dissolved and deposited again on the cathode via the aqueous solution.
Metals can also be deposited without using external current. For this purpose, special chemical substances such as complexing agents, stabilizers and reducing agents are added to the aqueous metal salt solution. Whenever a workpiece is dipped into such solution, the metal will deposit only on this piece. Using a suitable pre-treatment (activating, catalyzing) this process even permits to deposit metals on plastics.