What is electroplating?
Electroplating is a process that uses an electrical current to dissolve metal so that a metal coating is deposited on an electrode. This process is called electrodeposition. The part that is to be plated is called the cathode and the anode is made of the metal which is to be plated onto the component.
The parts to be plated are then placed in a solution called an electrolyte, which contains metal salts and ions which allow the electricity to flow through it. The power supply then directs the current to the anode, which oxidises the metal atoms that comprise it and allows them to dissolve in the solution.
Then, the dissolved metal ions plate onto the cathode from the electrolyte solution. The rate at which the cathode is plated is always equal to the rate that the anode is dissolved.
What is electroplating used for?
Electroplating is used to change the surface properties of an object. For example, electroplating may be used to build up the thickness on a part that is slightly undersized, or to form objects by electroforming.
Electroplating may also be used where abrasion, wear resistance, and corrosion protection are an issue, to increase lubricity and for aesthetic purposes. Unlike electroless nickel plating however, the process of electroplating makes the component subject to changes in the density of the current. This results in variations in the thickness of the electroplated deposit.
What is electroless nickel plating?
Electroless nickel plating is an auto-catalytic reaction which is used to deposit a coating of nickel on a substrate. The metal is deposited when a reducing agent reacts with metal ions. Unlike electroplating, it is not necessary to pass an electric current through the solution to form a deposit.
What are the advantages of electroless nickel plating over electroplating?
Electroless nickel plating has a completely uniform coating. This means that it is a perfect solution for critical high-end engineering items including defense, healthcare, automotive and aerospace.
Electroless nickel can be deposited to produce a wide range of coating thicknesses, with uniformity and minimum variation from point to point. This uniformity can be maintained in plating both large and small parts and on components that are fairly complex, with recessed areas.
Electroplating of such parts, on the other hand, would produce thickness variation and possible voids in the plating when coating holes and inside diameters. Also, with the proper pre-plate catalyst, electroless nickel plating can deposit on non-conductive surfaces.
What is electroless nickel plating used for?
Electroless nickel plating is a plating technique commonly used to prevent corrosion and wear. The electroless nickel plating process is a high quality, cost effective solution to coating metals such as mild steel or stainless steel and can substantially extend the life of a component.
Electroless nickel plating is extremely resistant to corrosion and will therefore extend the life of everything it coats. This makes it ideal for coating parts exposed to harsh environments such as those operating in the marine, oil and gas and defense industries. Therefore, it can also reduce the cost of repair and replacement parts.