Electroless Nickel Plating Industry Information

Electroless nickel plating is a process in which a coating of a nickel alloy (most commonly nickel-phosphorus) is deposited onto a metallic substrate. This is a procedure that uses heat, which is directly linked to the chemical reduction of nickel compounds. Unlike electrolytic coatings, electroless nickel plating is performed without the use of electricity. Electroless nickel plating also has better corrosion resistance compared to other coating techniques. Any substrate surface to which the coating solution has free access is capable of being coated or plated.

Electroless nickel plating was first reported in 1946 by its accredited discoverers, Grace Riddell and Abner Brenner. Nowadays, technology and education have enabled the advancement of the nickel plating process. Electroless plating is superior to electrolytic plating in its ability to coat uniformly. There is also less excessive buildup on projections and corners. Because of its benefits, electroless nickel plating is a favorite for coating irregular objects that other processes have difficulty covering. Products that have already been coated with electroless nickel can undergo heat treatment in order to precipitate phosphorous from the alloy, which increases hardness up to four times.

Various nickel deposits are available based mainly on the phosphorus concentration. Low phosphorus deposits (1-4%) have the ability to be welded or brazed, and are very corrosion resistant. For applications where lubricity and heat tolerance are desired, a medium phosphorus concentration (5-9%) is more beneficial. Maximum corrosion resistance for nickel plating comes with a higher phosphorus concentration (10-15%). High amounts of phosphorus add to the deposit's non-magnetic and excellent ductile qualities. Another property of phosphorous electroless nickel that makes it highly beneficial is its ability to adhere to most metals.

Some examples of industries that use electroless nickel plating include the petroleum, medical, dental, oil, gas, aerospace and automotive fields. After choosing the deposit best suited for a particular application, the thickness of the coating should be considered. Coating thicknesses for electroless nickel plating range from less than .0005 inches to over .01 inches. Thicker coatings often mean better corrosion resistance and better wear characteristics. This provided, finding a quality finisher is crucial in receiving a quality product. With all the advancements in electroless nickel plating, it is surprising that the exact mechanism for the deposition remains unknown, due to its complexity.