Copper plating is an electrochemical process in which a layer of copper is deposited on a solid metal surface by using an electric current.
Copper plating is an important process because:
It provides valuable corrosion protection.
It improves the wear resistance of the surface.
It has excellent adhesion to most base metals, improving the ductility of coated products.
It has excellent thermal and electrical conductivity, making plated products suitable for precision engineering applications such as printed circuit boards (PCBs).
Copper is one of the very good conductors of electricity. A layer of copper provides excellent electrical conductivity to many components. Therefore, copper plating is used in the electrical and electronic industries. Since copper is a soft metal, it can be applied to metal parts that require some flexibility. The copper layer will not flake off as it maintains adhesion to the metal surface, even under bending conditions. It provides even coverage on most non-ferrous metals and some ferrous metals.
In the copper plating process, copper sulfate is used as the electrolyte, the copper wire is immersed in the electrolyte as the anode, and the iron rod to be plated is immersed in the electrolyte and externally connected as the cathode.
When the circuit is connected and current flows, the copper sulfate (CuSO4) molecule splits into positive copper ions and negative sulfuric acid (SO4) ions. Positive Cu2 ions are attracted to the cathode iron rod. When the Cu2 ions reach the cathode, they take 2 electrons to form neutralized metallic copper, which is then deposited on the surface of the iron rod. The copper molecules in the copper anode become copper ions and lose 2 electrons. When they enter the electrolyte and chemically react with sulfate ions, copper sulfate is produced to rebalance the concentration of the electrolyte.
Copper plating as an undercoat provides excellent wear and corrosion protection for nickel-plated steel components. As a base plate, it provides an effective barrier between the substrate and subsequent metal deposits.
Copper plating is applied to perfectly cleaned and pickled steel products such as steel wire by an electrodeposition process. The copper layer protects the coating part from diffusion of carbon or cementation within the part. Copper plating is also used for protective chrome plating, where the copper forms the intermediate plate. The copper layer on the steel is plated with nickel and then coated with a thin layer of chrome for effective corrosion resistance.
