Electroless Nickel Plating, or ENP, is the process of adding a nickel-alloy coating to surfaces/substrates using a chemical reduction. This removes the need for an electric current.
How does ENP work?
ENP works by using a chemical reducing agent to reduce nickel ions to metallic nickel and applies this as a coating. Most coatings consist of between 2% and 14% phosphorus. Coating thickness tends to range from 25 to 75 microns..
The Benefits of Electroless Nickel Plating
ENP offers a number of advantages over other coating methods:
- Corrosion resistant: ENP coatings are resistant to salt water, oxygen, carbon dioxide and hydrogen sulphide.
- Amorphous: the high phosphorus deposit means there are no phase boundaries or grain which could potentially cause initiation sites for corrosion.
- Uniform finish: the coating created is of uniform thickness across the entire workpiece – even in inside walls, holes and slots.
- Safe: as there is no need for an electric current, the process is safer.
- Hard and wear-resistant: high phosphorus ENP offers good hardness and enhanced wear resistance.
What factors affect plating quality?
There are a range of factors that can impact the quality of ENP, including:
- Surface preparation: rough, uneven surfaces cannot be plated effectively, so good surface preparation is crucial.
- Surface cleanliness: to accept the coating effectively, surfaces must be free from dirt, oils and other contaminants.
- Plating bath quality: the temperature, nickel ion concentration, hypophosphite concentration, and PH of the plating bath all need to be carefully controlled.
Thermal plasma spray experts
If you are interested in learning more about thermal plasma spray coatings, there are a number of specialists, such as https://www.poeton.co.uk/surface-treatments/thermal-metal-sprays/plasma-coatings/, that can provide advice and services.
What to Consider
Before opting for ENP, you should make sure that it is the most effective and efficient plating method for your particular project. Consider the attributes that you want to imbue, and the size and dimensions of the workpiece. There may be alternative coating methods that better suit your needs.