Electroless Nickel Plating (ENP) is the process of depositing nickel alloy coating by chemical reduction. Unlike the electroplating process, ENP does not use electric current. In the majority of cases, ENP is used for engineering purposes. The composition of deposits typically consists of nickel phosphorous in the range of 2% to 4%.
With higher phosphorus contents, corrosion resistance increases while the hardness decreases.
Electroless Nickel Plating Benefits
- Excellent corrosion resistance to common corrodents such as saltwater, carbon dioxide, oxygen and hydrogen sulphide.
- Lower initiation of corrosion owning to porous nature of ENP deposits which eliminates the creation of grain or phase boundaries
- Uniform coating, especially for thick coatings across selective areas such as holes, slots
- Lower cost alternative to corrosion resistant alloys in applications such as critical valves, electrical components with higher risks to localised corrosion.
Factors that affect plating quality
There are several factors affecting plating quality and the majority should be effectively managed by your surface finishing partner.
– Surface preparation: Rough, badly machined surfaces with uneven metal surfaces, burrs or cold shuts cannot be effectively plated.
– Cleaning: Surfaces must be free from oils, dirt and soaps formed by saponification of oils by alkaline cleaners.
– Control of the plating baths: Temperature, pH, nickel ion concentration and hypophosphite concentration all need to be carefully managed to ensure high quality, consistent plating finish is achieved.
Factors to consider when selecting a plating provider
- Surface inspection process of the service provider before plating
- Quality of chemicals to be used in ENP and their certifications
- ENP solutions must be prepared with demineralised water
- Continuous filtration of the bath to one micron
- The monitoring system in place for bath chemistry
- Regular cleaning of the baths
- Quality and testing procedures for deposits
Sargam Industries offers reliable, safe and high-quality electroless nickel plating services for a variety of applications.