Electroless Nickel is a hard, smooth, coating that can cover complex geometries with excellent uniformity. It is applied to interior and exterior of nozzle cores and is resistant to oxidation, corrosion and abrasive wear. It is a nickel-phosphorous alloy deposited by a chemical reduction reaction from hypophosphite on a catalytic substrate without the application of external current.
Electroless Nickel with medium phosphorous content (5-9%P, Type 4) is used. It has a semi-bright silver appearance. It is magnetic and exhibits good corrosion resistance. Hardness is achieved by heating cores above 500°F per the schedule given in the specification after plating causing transition from an amorphous as plated state to a crystalline structure, greatly increasing hardness.
Electroless Nickel coatings have a minimum hardness of about Rockwell c 63 or equivalent. Nominal core coating thickness is about 0.0005 inch. Standard gage cores in phosphor bronze or nickel silver are available coated with this process. To specify this coating add 01 to the coating designator in the part number.