Electroless nickel plating is something that is used in a huge variety of industries, and on objects that we use every day in our own lives, but most people don’t know very much about it, despite its ubiquity.
An electroless plating is a metallic coating that is, as the name suggests, electroless. Whereas electroplating makes use of a process where an electrical current is applied to a chemical component, causing the chemical composition to shift and deliver a resistant coating to the surface of whatever is being plated. Electroless plating, on the other hand, is a non-galvanic process that does not use external electrical power. The process is actually simpler, using a variety of chemicals and proprietary solutions and not requiring the extra equipment that electroplating does.
There are several benefits to electroless plating over electroplating, including the ability to coat surfaces which would either be very difficult or impossible to coat via electroplating, and little to no excess deposit at high points. Engineers also have greater control over the deposition, meaning the final result is a smoother, more even coating. This greater control also means they can control the thickness and volume of the plating with far more precision.
Electroless nickel coating has great levelling, pore-filling and smoothing properties and has excellent wear and abrasion resistance. Its most common usage is in applications where its corrosion-resistant properties and hardness are needed. These are surprisingly varied. There are some obvious applications, such as marine engineering (where constant sea abrasion makes electroless nickel coating extremely useful and valuable) and the automotive industry, but there are also application that may not have sprung immediately to mind. One of these is the manufacturing of hard disk drives, where electroless nickel plating is used to deliver a smooth coating to the aluminium disks. Other applications include items which see a great deal of everyday use, such as door knobs or kitchen utensils. Electroless nickel plating can also be used for decorative purposes, thanks to the greater control over the coating given by its electroless qualities.
The benefits of electroless nickel plating don’t stop with its corrosion-resistant properties or its hardness. It also will not chip, flake or peel the way many other coatings will, and its hardness can be increased with heat treatment. It can also be used to plate unusual or irregular shapes smoothly, making it extremely useful for applications where there are crevices or uneven surfaces.
Electroless nickel coating can be found in many different industries and in often surprising places, but the reasons why are clear: it is unmatched in what it offers, and a clear rival is yet to be found. Until a strong competitor emerges, electroless nickel plating will continue to be ubiquitous.