An electroless nickel coating is created when an auto-catalytic chemical technique is used to deposit a layer of nickel onto a solid component, usually plastic or metal.
The metal is deposited when a reducing agent reacts with metal ions. The metallurgical properties of electroless nickel alloy depend on the percentage of phosphorus present in the deposit. Phosphorous content can range from low (2-5) to high (11-14).
Nickel electroplating is a process which results in the deposition of nickel onto a metal part. Electroplating is achieved by immersing the component into an electrolyte solution so that the component itself is used as the cathode. The nickel anode is then dissolved into the electrolyte solution of nickel ions. The ions travel through the solution and are then deposited on the component.
A thin layer of nickel is deposited onto the metal object, which can provide corrosion and wear resistance, or be used to build up parts that have been worn down over time. Unlike electroless nickel plating however, this process makes the component subject to changes in the density of the current. This results in variations in the thickness of the electroplated deposit.