Electroless nickel plating (ENP) is a process that is used to add a nickel-alloy coating to the surface of an item or part. Unlike standard electroplating, it does not need an electric current, utilising only chemical reductions.
How does the process work?
There are three main steps in the ENP process.
1. Pre-treatment: this involves thoroughly cleaning the surface of the parts using various chemicals. This removes dirt, greases, oils etc.
2. Activation: the surface is ‘activated’ using acidic chemicals which remove oxides.
- Plating: this is where the parts are placed in the ENP bath so that the coating can be added. The coating thickness can be precisely controlled.
After the plating is complete, the parts will be inspected and tested to ensure the desired finish has been achieved.
What are the main benefits?
ENP offers excellent resistance to corrosion from a range of elements including salt water, carbon dioxide, oxygen and hydrogen sulphide. The corrosion-resistance level can be controlled by adjusting the phosphorus content in the ENP bath.
ENP offers good levels of overall hardness. This can be increased using heat treatment if required.
The thickness of ENP coatings can be precisely controlled, and their uniformity is superior to those created using electrolytic deposits. They can be used on a wide range of substrates including slots, holes and inside tubes.
ENP is a cost-effective solution for extending the service life of parts.
Electroless nickel plating specialists
If you feel that electroless nickel plating is something that would benefit you or your business, there are a number of experts in this sphere, such as www.poeton.co.uk/standard-treatments/electroless-nickel-plating/ .
What is ENP used for?
ENP offers many advantages (outlined above), and is used in a range of industries such as aerospace, electronics, construction and engineering. Examples of items that often have ENP coatings include drive shafts, engineering equipment, electrical/mechanical tools, valve pumps and more.
Any drawbacks?
The main drawbacks of ENP are that the process requires constant monitoring and the chemical bath that is used has to be replenished regularly.
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