Electroplating.

Copper plating by galvanization is the coating of another material with copper using the phenomenon of electrolysis. The anode - which is the source of copper - and the cathode - which is the place of copper deposition - suspended in the bath, connected to an electric current, force the movement of Cu 2+ copper ions, which migrate from the anode - dissolved as a result of the process - through the electrolytic bath to the cathode on which the copper is put aside. Electrolytic copper plating can be carried out in various types of baths. The most efficient and durable are the so-called acid baths. The coatings obtained per unit of time as a result of their use are much thicker than, for example, using cyanide baths. However, acid baths have their limitations, e.g. steel or iron objects cannot be coppered directly in them. Because copper plating is a great protection, e.g. against carburizing or nitriding, it is often used indirectly. That is, the steel objects are first pre-coppered in a cyanide bath. Obtaining the initial layer of copper and then proper copper plating takes place in a much more efficient process using an acid bath.
The most commonly used acid bath is a bath prepared on the basis of copper sulphate and sulfuric acid with the following composition:

- 1 liter of distilled water heated to at least 18-20 degrees Celsius.
- 200 g of crystalline cupric sulphate pentahydrate.
- 25 ml of concentrated sulfuric acid.

The copper anode and objects attached to the cathode that are to be coated with copper can be introduced into the bath prepared in this way.
Copper plating in an acid bath requires a stable bath temperature in the range of 18-20 degrees Celsius and continuous but not intensive stirring of the bath. Before starting the process, the anodes should be cleaned and pre-activated, e.g. by etching in 8% nitric acid for several seconds. In the process, we use a current density of 1-2 A/dm2 and a voltage of 2-3 V. As a result of an hour-long process, we obtain an average coating thickness of 30 um, i.e. 0.03 mm. In order to obtain thicker coatings, the duration of the process is proportionally extended. During copper plating, the condition of the coating should be checked every 20 minutes - of course without switching off the power. If defects are found, especially on corners and sharp edges, but also stains and discoloration on the face surfaces and the formation of the so-called coarse-crystal infiltrations, the current intensity should be immediately reduced, and the quality of the applied coating should immediately improve. After the copper plating is completed, the remains of the electrolytic bath should be removed from the workpiece as soon as possible. This is best done by rinsing vigorously under running tap water. The element deactivated in this way can be dried, e.g. in sawdust and passivated, e.g. by covering it with a layer of oil, or directly sent for further electrolytic treatment. Copper is often not the final coating but an intermediate coating intended to be a well-adhesive base for the next layer of silver, silver and gold, nickel, nickel and chromium, tin.

Crystalline cupric sulphate pentahydrate available at distripark.com .

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*This article is for informational purposes only. The presented description, in particular the use of the products, is exemplary and constitutes non-binding information about the characteristics and possibilities of their use/application. In any case, before using the product, consult a specialist whether the specific use is safe and justified. We do not bear any responsibility for the use of the proposed solutions, even in very similar situations.

*This article is for informational purposes only. The presented description, in particular the use of the products, is exemplary and constitutes non-binding information about the characteristics and possibilities of their use/application. In any case, before using the product, consult a specialist whether the specific use is safe and justified. We do not bear any responsibility for the use of the proposed solutions, even in very similar situations.