Classification of Electroplating Processes

Electroplating processes can be grouped as follows:

1. By Type of Current

   1. Direct‑Current Plating (DC Plating):The most common method, using a steady DC power source.
   2. Pulse‑Current Plating:Uses pulsed DC to improve coating quality and properties.
   3. Alternating‑Current Plating (AC Plating):Uses AC power, mainly for special applications such as electrochemical polishing.

2. By Plating Material

   1. Metal Plating: Depositing pure metals, e.g. copper plating, nickel plating, chrome plating, gold plating, silver plating.
   2. Alloy Plating: Depositing alloys, e.g. brass plating, bronze plating.
   3. Non‑Metallic Plating:Depositing non‑metal layers, e.g. phosphate plating, oxide plating.

3. By Bath Chemistry

   1. Acid Plating: Uses an acidic electrolyte solution.
   2. Alkaline Plating: Uses an alkaline (basic) electrolyte solution.
   3. Neutral Plating: Uses a neutral‑pH electrolyte solution.

4. By Process Configuration

   1. Tank (Rack) Plating: Workpieces are hung on racks and immersed in a plating tank—the most common setup.
   2. Barrel (Tumbling) Plating: Small parts are loaded into a rotating barrel to tumble in the plating solution, ideal for bulk production of small components.
   3. Brush (Selective) Plating: A brush or pad saturated with plating solution applies current locally—suited for complex shapes and spot repairs.
   4. Electroless (Chemical) Plating: No external current; metal ions are chemically reduced onto the substrate, e.g. electroless nickel plating.

5. Other Specialized Methods

   1. Vacuum Plating: Performed in a vacuum chamber, used for very thin coatings.
   2. Ion Plating: Uses an ion beam to deposit metal onto the substrate, also for thin, high‑adherence films.
   3. Plasma Plating: Employs plasma technology to enhance coating quality and adhesion.