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Electroless Nickel Plating
Electroless
Nickel is an autocatalytic chemical reduction process (no
electric current is used) that deposits a nickel-phosphorus
alloy in a uniformly hard, highly protective finish. By
increasing surface hardness, Electroless Nickel improves
resistance to friction, wear and corrosion. Our process prolongs
by 2-to-10 times the service life of parts and components.
Different Electroless Nickel baths produce different deposit
characteristics. Since no anoding is required, edge buildup is
virtually eliminated.
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Electrolytic Nickel |
Electroless Nickel |
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The uniformity of the coating obtained from electroless nickel
plating, makes it highly suitable for use on engineering
components as the machined tolerances of a component are not
deformed by the plating process. The uniformity of the coating
and the fact that it is a chemical reaction, give the
electroless nickel deposit a number of properties which are
advantageous to many applications.
Applications for
Electroless Nickel:
The hardness and corrosion resistance of electroless nickel
are key factors in many successful applications. These
coatings are used for a variety of applications including
electrical connectors, microwave housings, valves and pump
bodies, printer shafts, hard drive computer components and
more. These unique coatings are applied to impart corrosion
protection, wear resistance, to provide solderability, to
provide a non-porous barrier layer, or otherwise enhance the
performance or useful life of a particular component.
Electroless nickel is used to coat components made of steel,
stainless steel, aluminum, copper, brass, magnesium and a
number of non-conductive materials. They are used in such
diverse industries such as the automotive industry, chemical
process industry, the oil and gas industry, the aerospace
industry and the electronics industry.
We offer 100% lead free and / or cadmium free component
systems to comply with "green" initiatives. The largest
growth area for these coatings outside of electronics has
been the automotive industry. This segment has specified
electroless nickel on a number of brake, transmission,
steering assembly components and other parts.
Coating
Hardness and Heat Treatment: The
hardness of electroless nickel is a key factor in many
successful applications.
The hardness of electroless
nickel coatings can be enhanced by heat treatment and is
dependent on phosphorus content and heat treatment time and
temperature.
Electroless Nickel can be hardened to Rc68 by heat treating
at 650 - 700°F (343 - 371°C) for one hour. Electroless
Nickel provides a dramatic increase in hardness, compared
with electro-deposited nickel (Rc46 as deposited) and
standard chrome baths ( Rc 62 - 64 as deposited ).
Finish/Brightness : Electroless
Nickel does not substantially affect the surface finish of
parts. A part with a 15 micro-inch finish prior to plating
will have approximately the same finish after plating. All
components must be ground or polished to final finish prior
to plating.
Deposit Ductility :
Electroless
nickel deposits are not considered to be "ductile" due to
their high hardness. However, there is a relationship
between ductility and phosphorus content which is outlined
in below graph
Corrosion
Resistance :
The surface condition of the substrate can have a
significant effect on the ability of the electroless nickel
coating to serve as a barrier to corrosion. Generally,
thicker deposits are suggested for rougher substrates, such
as castings, to insure low porosity and optimum corrosion
resistance.The different classes of electroless nickel
coatings, either low, medium or high phosphorus, may not all
perform in the same manner in a corrosive environment. For
example, the low phosphorus electroless nickel coatings will
tend to corrode less in strongly alkaline environments (such
as a low phosphorus electroless nickel plated valve in a
chlor-alkali manufacturing plant), than any other
electroless nickel coating. Similarly, the high phosphorus
electroless nickel coatings tend to be more amorphous or
"glass like" in structure and tend to perform superior to
other electroless nickel coatings in strongly acid
environments.
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