Electroplating equipment - basic principles of electroplating

The R & D, design, manufacturing, sales and service of electroplating equipment and ultrasonic cleaning equipment are integrated. Electroplating is not only an electrochemical process, but also a redox process The basic process of electroplating is to immerse the parts in the solution of metal salt as the cathode and the metal plate as the anode. After being connected to the DC power supply, the required coating is deposited on the parts.

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

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

2H + + 2e → H2 ↑ (side reaction)

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

4OH - - 4E → 2H2O + O2 + 4E (side reaction)

Not all metal ions can be deposited from aqueous solution. If the side reaction of hydrogen ion reduction to hydrogen on the cathode is dominant, it is difficult for metal ions to precipitate on the cathode According to the experiment, the possibility of electrodeposition of metal ions from aqueous solution can be obtained from the periodic table of elements,

Anodes are divided into soluble anodes and insoluble anodes. Most anodes are soluble anodes corresponding to the coating, such as zinc anode for zinc plating, silver anode for silver plating, and tin lead alloy anode for tin lead alloy However, due to the difficulty of anode dissolution, insoluble anodes are used in a few electroplating. For example, platinum or titanium anodes are mostly used in acid gold plating The main salt ion of the plating solution is supplemented by adding the prepared standard gold containing solution Chromium plated anodes use insoluble anodes such as pure lead, lead tin alloy and lead antimony alloy.