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Sharretts Plating Company, Inc.
P.O. Box 157
Emigsville, PA 17318
P: 717-767-6702
F: 717-764-0528
E: spc@sharrettsplating.com
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Home > Electroless Nickel Plating > Types

How Do I Know Which Type of Electroless Nickel Plating to Use?

Step 1: Answer these questions to determine which you need:

  • Describe the industrial application for this part.
    What traits are needed? Some examples may be magnetism and conductivity.
  • Describe the environment which the parts are going to be exposed.
    How many hours of atmospheric testing must the parts pass and at what temperatures?
  • Quantify the needed hardness (Rockwell or Vickers) of the finish after plating.
    Is the part being impacted or worn to a specific force level?
  • What is the acceptable coating weight loss (according to the Tabor Wear Index)?
  • Describe the next manufacturing steps.
    Does the part get soldered or bonded? Will there be another finish applied on top of the electroless nickel?

Step 2: Choose the right electroless nickel plating for your parts.

Below is a list of our electroless nickel plating solutions that produce various desired outcomes depending on your application end use need.

Click on products for more details.

Electroless nickel CORROSION PROTECTIVE FINISHES

Electroless nickel WEAR RESISTING FINISHES

Low Phosphorous Electroless Nickel

This electroless nickel bath contains up to 5% phosphor and was developed to handle higher temperature environments, offer increased hardness and reduced wear, and due to the low amount of alloyed phosphor it inhibits better solderability, and increased electrical conductivity. Corrosion protection is poor when exposed to acidic environments as compared to good protection in high pH (alkaline) environments e.g. chemical manufacturing of caustic soda and chlorine. This alloy creates compressive stress which decreases fatigue failure on steel alloys. This is a more economical choice as compared to Boron electroless nickel deposits.

Mid Phosphorus Electroless Nickel

Containing 5% to 9% phosphor, mid phosphorous electroless nickel has moderate corrosion and wear resistance. This coating is typically bright. The bath is the most economical as compared to the other electroless nickel bath formulations. It is a great choice for bringing back tolerance of under-sized parts. One key problem is that this bath creates a moderate level of tensile stress as deposited onto steel.

High Phosphorous Electroless Nickel

High Phosphorous Baths are defined as having above 10% phosphor and form the best quality deposit for most corrosive atmospheres since they form a true amorphous (glass like) surface absent of any crystalline structures. They typically do not contain more than 13% phosphor in their deposits. High phosphorous electroless nickel is completely non magnetic as plated and is a great choice for electronics that need shielding characteristics to stop interference from other electronic devices.

Boron Electroless Nickel

This electroless nickel baths contain 0.5% to 5% boron. There are two main classes of Boron electroless nickel coatings. The first class contains lower amounts of boron (0.5% – 3%) for improved solderability and conductivity meant for use in the electronics sector. The second class of these coatings is utilized for their increased hardness and resistance to wear as compared with phosphorous electroless nickel coatings. The high boron electroless nickel (3-5%) coating as plated is as hard as chrome and can be heat treated further to exceed that hardness level. This second class of boron electroless nickel coating is used mostly in the automotive and aerospace industries as a replacement for chrome plating. However boron electroless nickel coatings are a poor choice for corrosion protection as compared with phosphor electroless nickel coatings because they have higher internal deposit stress which creates more porosity.

Composite Electroless Nickel Coatings

electroless nickel composite coatings are created by adding particles into the bath which then become occluded (deposited) with the nickel alloy. These particles range in size from 0.5 – 10 um (20 – 400 u") in diameter. The average composite electroless nickel coating contains anywhere from 10 – 30% particles. These composite coatings are married well with any matrix electroless nickel baths and can combine both hard and soft particles in one uniform coating. The potential outcome the new electroless nickel matrix will vary upon the ratio of hard and soft particle volume and also by the method applied.

Carbides/Diamonds

Ceramics and minerals are very hard and in many cases nearly indestructible. They serve as a great choice since they have very high hardness values and also have very high melting points thus reducing abrasion and wear loss of the overall electroless nickel composite coating. Composite coatings are rough and dull as plated. Post plating grinding and buffing may improve the visual aesthetic. These coatings are more expensive (see below table) compared to boron and phosphor electroless nickel plating by themselves. Some examples of the types of particles are aluminum oxide, silicon carbide, tungsten carbide, and in rare cases diamonds or other mined minerals.

Polymers

Polymers such as fluorocarbons are used to minimize friction of a part and also reduce wear. Most electroless nickel composite polymer coatings have a range of 10 – 30% particle composition by volume. These polymers can be evenly dispersed and occluded into the nickel coating. The coating produces a matte grey to chalk white appearance as plated. The most popular fluorocarbon coating is Teflon™. Particle sizes are of the same range as hard particle sizes. These coatings create good release and anti-galling properties. Most polymers have much lower melting points as compared to hard particles and begin to melt around 330° C (626° F) such as Teflon™ while there are other fluorocarbons that have higher melting points nearer to 1000° C (1832° F).