What Are the Differences Between Electroless and Electrolytic Nickel Plating?

The discovery of nickel in 1751 was vital to the growth of industry. Its natural resistance to corrosion made it the perfect material to protect machinery from wear and degradation. Industrial nickel plating was developed a century later, and the principles established in the 1860s remain the basis of nickel plating today.

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The evolution of nickel-plating is inseparable from the history of industrial innovation, and on both sides of the Atlantic successful businesses were founded to meet the needs of manufacturers to protect and preserve their increasingly sophisticated and expensive machinery. Some businesses, like the British family enterprise Poeton, were there at the beginning and remain leaders in research and development to this day.

Electrolytic and Electroless

Processes have changed over the decades, and although nickel remains the key ingredient, methods of application have diversified. Two of the most common alternatives are electrolytic and electroless nickel plating. To many industrialists the distinctions might not be obvious, but there are fundamental differences to take into account when considering which process to select.

Electrolytic nickel plating involves the application of a layer of nickel to a substrate of metal or alloy using a catalyst and a DC electrical charge to produce a chemical reaction. This causes the nickel to form a protective coating on the substrate.

Electroless nickel plating creates the same effect but by different means. As its name suggests, it requires neither catalyst nor charge, instead employing a chemical reducing agent that makes it possible to coat the surface and dispense with extra levels of processing.

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Which Is Best?

So far so similar, but beyond the method of application lie considerable differences. As industry experience has shown, and the findings of the Surface Engineering Association (SEA) have echoed, not only is electroless more straightforward, it generally results in a consistent uniform coating as well as providing more robust resistance to corrosion and wear, greater performance and enhanced lubricity.

Electrolytic plating can produce a thicker coating of 100% nickel, whereas electroless involves the addition of phosphorus. Electrolytic coating is also cheaper and has better conductivity, making it suitable for high-volume production. Electroless, on the other hand, is extremely precise and the coatings not only reduce friction but are more resistant to cracking under the pressures of industrial use.

Both processes have their advantages, so it’s essential to select the one which will yield cost-effectiveness and efficiency.