There are many different performance benefits of electroless nickel. Electroless nickel plating is far superior to electrolytic nickel plating. It is characterized by excellent corrosion resistance, lubricity, long wear life, and even distribution.
One of the main benefits of electroless nickel plating is corrosion resistance. Erie Hard Chrome uses a high-phosphorus nickel bath. The phosphorus content is 10% to 12%. The high-phosphorus bath gives the highest corrosion protection of all electroless nickel baths.
Another benefit of electroless nickel plating is adhesion. With proper surface preparation, excellent adhesion can be obtained by electroless nickel plating. Metzger has reported bond strengths of 30,000-60,000 lbs. per square inch for the electroless nickel on mild steel. On other substrates, Erie Hard Chrome's electroless nickel plating is generally lower.
The electroless nickel coating we use has passed the 180-degree bend test specified by MIL-C 26074 without any sign of flaking. There will usually be macroscopic and microscopic cracks in the coatings parallel to the direction of bending. On properly prepared surfaces, this cracking is not accompanied by flaking but demonstrates that adhesion of the coating is greater than the cohesion of the deposit.
Another benefit of electroless nickel plating is hardness. Our electroless nickel deposits have a hardness of 45Rc to 48Rc as plated. This can readily be increased to 68Rc by heat treating at 750°F (400°C) for one hour. Further heating above 750°F (400°C) tends to reduce the hardness, but at the same time increases the ductility due to the growth in crystal size.
Brightness is another benefit of electroless nickel plating. Our electroless nickel baths produce a semi-bright deposit. Our solutions preserve any finish of the substrate surface.
Since our electroless nickel deposits are uniform in thickness, they permit the complex plating of intricate shapes and patterns which is another electroless nickel plating performance benefit. Industrial diamonds as small as 125-grit and the cavity of a 7-ton steel mold for molding plastic have been successfully plated with electroless nickel.
In electroplating, the distribution of nickel plate varies with current density. Since edges and sharp corners are high current density areas, there is a buildup of electroplated nickel at these points. With the uniform deposit of electroless nickel, these variations are eliminated. If one mil of electroless nickel is deposited on the outside of a tube, then one mil will be deposited on the inside. A needle plated with electroless nickel is still a needle without nodular growth found in electroplated deposits.