COPPER
Copper electrodeposits are primarily used as either an underplate or strike
layer for a subsequent plated deposit or can be used alone primarily as
a stop-off or mask for heat treatments, electroforming, and printed circuit
plating applications. Deposits come from either alkaline or acidic electrolytes. |
CADMIUM
Cadmium deposits are used primarily on steel to aid in corrosion resistance
usually with the addition of a chromate layer over the cadmium deposit.
In addition to good corrosion resistance, cadmium also offers a variety
of engineering qualities including lubricity, excellent electrical conductivity,
low contact resistance and good solderability. Most cadmium deposits
are produced from cyanide baths. |
ELECTROLESS COPPER
Deposited from solutions, which are autocatalytic and are designed primarily
for through-hole plating of printed circuits. The deposit can also be
applied to certain plastics such as ABS after pretreating the material
to accept the electroless deposit. Current technology offers solutions
with relatively low stressed deposits and the need for extensive pretreatment
conditioning. |
ELECTROLESS NICKEL
Used to deposit a nickel plated deposit on various substrates without the
use of an electrical current. The deposit comes from an autocatalytic
chemical reduction of nickel ions by hypophosphite compounds in either
low, medium or high phosphorus plating baths. Electroless nickel deposits
offer excellent wear resistance, corrosion resistance and good solderability. |
NICKEL
Nickel deposits are general-purpose plated deposits, which are used primarily
for corrosion resistance and for build up of worn or undersized parts.
Additional characteristics of the nickel deposit include an aid to subsequent
brazing operations. Deposits usually are from an acid based solution. |
SILVER
Primarily deposited from a cyanide bearing bath, silver deposits are used
within the requirements of industry for solderability, lubricity and
as an anti-galling coating. Silver deposits also offer some unique corrosion
resistance characteristics, which makes the deposit useful in some medical
applications and some chemical applications. Supplementary chromate coatings
are available to inhibit tarnishing of the silver deposit. |
GOLD
Gold plated deposits are used primarily for conductivity and solderability
purposes with emphasis on the printed circuit or electronics industries.
Purity of the gold is important depending on the application and typically
is between 99.97%-99.99%. Baths used for gold deposits can be cyanide,
acidic or neutral and all are controlled |
TIN
Some of the most desirable properties of electrodeposited tin include excellent
solderability, ductility, softness and corrosion or tarnish resistance.
Tin deposits will provide sacrificial protection to copper, nickel and
some other nonferrous alloys, but will not provide the same protection
to steel in a normal atmosphere. Primarily deposited from an acid based
bath, tin deposits will exhibit a bright, lustrous finish when applied
to the base metal. |
ZINC
Used primarily for corrosion resistance, zinc plating can be accomplished
utilizing rack, barrel, or continuous plating. Chromates are used for
enhanced corrosion resistance and applied over the plated deposit. Baths
are either alkaline or acidic. |
ZINC-NICKEL
Zinc-nickel coatings are considered alloy deposits of which both zinc and
nickel are in the plated deposit. Typical plated deposits contain between
6%-20% nickel with the remainder of the deposit as zinc. Zinc-nickel
deposits are utilized in applications where superior corrosion resistance
is required. A supplementary chromate is applied over the deposit for
enhanced corrosion resistance. Chromate colors range from clear, yellow,
iridescent and black and is dependent upon percentage of nickel in the
plated deposit. |
ANODIZING
Anodizing is the chemical process used on aluminum in which the workpiece
is anodic and the conversion of the aluminum surface into aluminum oxide.
Some of the primary reasons for this process include: increased corrosion
resistance, increased paint adhesion, allow for subsequent plating operations,
improve decorative appearance, provide electrical insulation and create
unique, decorative colors. The anodizing process is performed in an acidic
bath and is temperature and current controlled. |
PHOSPHATING
Phosphate coatings are usually applied to steel, iron, galvanized steel
or aluminum for the purpose of wear resistance and anti-galling. Phosphate
processing is applied in an acidic bath and creates a mildly protective
layer of insoluble crystalline phosphate at the surface of the workpiece.
Typical applications can range from nuts, bolts, internal combustion
engine components and automobile parts. |
CHROMATE CONVERSION
COATING
Chromate conversion coatings are formed on metallic surfaces as a result
of chemical attack that results form the immersion of the workpiece into
a bath containing chromic acid, chromium salts and other mineral acids
leaving a protective film on the surface. These chromates are most widely
applied on plated deposits as well as chromates applied directly to aluminum.
The primary purpose of the chromate coating is to provide some form of
enhanced corrosion resistance to either the plated deposit or the base
material. |
BLACK OXIDE
Blackening is accomplished by a chemical immersion of the workpiece into
an alkaline sulfide solution and producing a metal sulfide finish. Color
can vary depending on chemical makeup and a protective layer is usually
applied to the blackened finish prior to use. The primary purpose of
the blackening process is to provide minimal corrosion protection, lubricity,
and cosmetics.
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