Diamond Tools Basic Principles of Electroplating

Basic principles of electroplating：

Many diamond tools require electroplating. Electroplating is an electrochemical process and an oxidation-reduction process. The basic process of electroplating is to immerse the parts in a solution of metal salts as the cathode and the metal plate as the anode. After connecting to a DC power supply , depositing the required coating on the part.

For example: when plating nickel, the cathode is the part to be plated and the anode is a pure nickel plate. The following reactions occur at the cathode and anode respectively:

Cathode (plated parts): Ni2++2e→Ni (main reaction)

2H++e→H2↑ (side reaction)

Anode (nickel plate): Ni -2e→Ni2+ (main reaction)

4OH--4e→2H2O+O2+4e (side reaction)



Not all metal ions can be precipitated from aqueous solutions. If the side reaction of reducing hydrogen ions to hydrogen dominates the cathode, it will be difficult for metal ions to precipitate on the cathode. According to experiments, the possibility of electrodeposition of metal ions from aqueous solutions , certain rules can be obtained from the periodic table of elements, as shown in Table 1.1



Anodes are divided into soluble anodes and insoluble anodes. Most anodes are soluble anodes corresponding to the coating. For example, zinc plating is a zinc anode, silver plating is a silver anode, and tin-lead alloy plating uses a tin-lead alloy anode. But a few electroplating Due to the difficulty in dissolving the anode, insoluble anodes are used. For example, acidic gold plating uses mostly platinum or titanium anodes. The main salt ions of the plating solution are supplemented by adding a prepared standard gold-containing solution. Chrome plating anodes use pure lead, lead-tin alloy, Insoluble anodes such as lead-antimony alloys.