Black (directly on Zinc Die Cast)
NBP's own formulations - This molybdate black goes directly on zinc die cast. After the molybdate coating is applied, the parts are submerged in a seal composed of chromates and phosphates that enhance the salt spray resistance of the coating. An organic coating, water dip lacquer, is applied as a final coat to protect the finish and improve appearance.
 

Black Chromate (Molybdate) on Zinc
Similar to Econo Black, but this molybdate black is applied over a bright zinc plate to yield a glossy, plastic like black finish. The corrosion characteristics can be improved with a seal and/or lacquer as required.
 

Black Electroless Nickel
Parts are Electroless Nickel plated and then blackened to give a metallic brown / black appearance. This coating is used for a variety of applications from color identification to eye appeal. The black coating doubles the contact resistance, but does not change the other properties of the electroless nickel plating.
 

Black Electrolytic Nickel
ULTRA CONDUCTIVE - This finish is not as intense as the Zinc & Black Chromate (Molybdate) but has excellent eye appeal, yet this finish in contrast to the other black finishes is very conductive. This coating was developed for automotive applications where conductivity and low reflectivity are important.
 

Blue on Electroless Nickel
The process is similar to black electroless nickel, but the color is a dark blue. There has been an increasing demand for different colors for identification purposes.
Chromate Coatings
 

Chromate coatings are chemical conversion coatings. The substrate metal participates in the coating reaction and becomes a component of the coating. The collaboration has a profound effect on the properties of the coating. Among the metals commonly chromate are zinc, zinc die casting, aluminum and sometimes copper and silver. Chromate films are typically very thin, on the order or .0000001 in. and contribute no measurable thickness to the overall coating.

 

NBP offers the following Chromates:
(and their resistance to white corrosion)
Clear - (8 to 12 hours) It has a slightly iridescent blue appearance.
Black- (48 hours)
Yellow - (in excess of 96 hours) Excellent paint base. Yellow Chromate (directly on Zinc Die Cast)
Olive Drab- (150 hours) dark green finish

Seals are offered for after chromates to increase corrosion resistance.

 

Copper
Copper is most commonly used as an underplate or strike because of its excellent adhesion and ductility. Deposited from a cyanide solution, copper is the best available deposit for plating direct on zinc die-cast.
Chrome Replacement (Cobalt-Tin)

This finish is very similar to chrome in its appearance and applications. Parts are plated first with a bright nickel then flashed with cobalt-tin to give a convincing appearance of a chrome-plated part. Finish is hard and durable. The alloy is a composite coating like a tin nickel.
 

Electroless Nickel
Unlike conventional electroplating, no electrical current is required for deposition. The electroless bath provides a deposit that follows all contours of the substrate exactly, without building up at the edges an corners. A sharp edge receives the same thickness of deposit as does a blind hole.

The most widely used engineering form of electroless plating is, by far, electroless nickel. Electroless nickel offers unique deposit properties including uniformity of deposit properties in deep recesses, bores and blind holes. Most commercial deposition is done with an acid phosphorus bath owing to its unique physical characteristics, including excellent corrosion, wear and abrasion resistance, ductility, lubricity, solderability, electrical properties and high hardness.
NBP offers different types of Electroless Nickel

Low Phos - A hard deposit approaching hard chrome with no heat treatment necessary for hardness. Comparable to boron electroless nickel. This deposit is used mainly for its hardness and wear properties.

Mid Phos – By far the most widely used deposit. It has a Bright uniform appearance and is used for both decorative and electronic applications.

High Phos - Compressively stressed deposits with excellent adhesion, ductility, and superior corrosion resistance.

Black on Electroless Nickel

Blue on Electroless Nickel
 

Gold
Because gold does not oxidize at normal temperatures it retains its conductivity and solderability. Even very thin layers will impart its properties to the plated surface. Gold is primarily used it the electronics industry for connectors, printed circuits, transistors and integrated circuits, anywhere where contact resistance, solderability, or wire bonding are crucial. Alloying Gold with small amounts of Cobalt can dramatically increase its hardness and wear characteristics. The excellent physical and chemical properties offset the price of gold.
NBP offers the following Gold Plating:

Pure Gold – 99.90%, 90 HK25
Hard Gold - 99.7%, 130-200 HK25 (Grade C)
Hard Gold – 99.7% >200 HK25 (Grade D)
Electroless Gold- 99.90%, 90 HK25
Immersion Gold – By substituting nickel as an undercoat instead of electroless nickel, immersion gold is only about 10% more expensive the electroless nickel alone. It is relatively inexpensive and an affordable finish.
 

 

Indium
Indium is a precious metal that has the unique quality of forming an intermetallic layer at room temperature with aluminum and copper. Thus, allowing for no oxidation to penetrate the aluminum or copper stock which will cause a short. This coating is the UL approved finish for connecting aluminum wiring to a copper receptacle.

 

Nickel
Nickel Plating is a yellowish white, hard reflective finish used for wear resistance, solderability, or dimensional restoration. Nickel plate is often applied over copper and under chromium for a decorative finish. For applications requiring bright nickel, there are other considerations. Nickel brighteners increase brightness, internal stress, and lower the ductility. It is best to avoid specifying bright nickel if the parts are to be bent or crimped after plating. For those instances, a Watt's nickel (nickel sulfate with little or no brighteners) is used. This semi bright nickel has a more satiny finish than bright nickel but is more ductile. If heat shock or minor bending of the parts is anticipated it would be better to specify semi bright nickel in order to reduce the risk of the plating flaking off.
 

NBP offers the following Nickel Plating:
Bright Nickel
Black Nickel (Ultra Conductive)
Blue on Electroless Nickel
Electroless Nickel
Watt's Nickel (Sulfamate)
 

 

Olive Drab
A dark green finish that can pass 150 hours to white corrosion. See Chromate Conversion

 

Passivation
Passivation of stainless steel is not electroplating, it is a non electrical process whereby the free iron is chemically removed from the surface of stainless steel. This prevents the formation of possible corrosion sites and the development of tightly adhering oxides. The 300 series alloys are generally preferred for Passivation, as some of the 400 series alloys will actually be discolored by the Passivation process. Passivation imparts a limited neutral salt spray corrosion protection to the stainless steel, usually not much over 2 hours. Since different solutions are used to passivate different alloys, they must be properly identified. Mixing alloys may not only result in differences in appearance, but may result in some parts being destroyed.

 

Silver
Silver has an advantage of its relative low cost, but it is susceptible to tarnishing when exposed to sulfur in the atmosphere. Silver plating, in addition to being decorative, has the highest electrical and thermal conductivity of any metal. It is highly ductile, malleable, and solderable. Silver tarnishes easily. Matte silver plate is used extensively for finishing electronic components where silver's mechanical properties of silver plate alone may not be enough and the design engineer feels that appearance may also be an important consideration.
 

 

Tin
Tin plating is normally done to impart solderability to variety of base metal substrates. Tin is a silvery, blue-white metal that is ductile, solderable, and covers very well. The solderability of time can be affected by the substrate, since several metals tend to react with and migrate into the tin forming relatively non-solderable intermetallic layers. Of particular concern is tin plating over brass or zinc die-cast. The zinc will migrate into the tin and severely limit the shelf life of the finished parts. The migration can be mitigated by the common practice of applying an undercoat of copper or nickel or a combination of copper with a flash of nickel through which the zinc cannot migrate. Matte tin generally has better solderability, but bright tin is specified more because of its appearance. Tin does not tarnish easily, making it a good choice as a decorative finish.
NBP offers the following Tin Plating:

Bright Tin
Matte Tin
Tin/Lead 60/40, 90/10, 93/7
Tin-Nickel

 

Yellow Chromate (directly on Zinc Die Cast)
Parts are first chemically milled then chromated to give a dull almost olive drab finish. Chromate coatings are chemical conversion coatings. The substrate metal participates in the coating reaction and becomes a component of the coating. The collaboration has a profound effect on the corrosion properties of the coating, in excess of 96 hours to white corrosion. Special seals can be applied which increase corrosion resistance to over 500 hours. Among the metals commonly chromate are zinc, zinc die-casting, aluminum and sometimes copper and silver. Chromate films are typically very thin, on the order or .0000001 in. and contribute no measurable thickness to the overall coating.


Yellow Chromate on Zinc
Same as above but with a bright yellow iridescent finish.


Zinc
Zinc plating is a soft, ductile, decorative, marginally solderable, corrosion-resistant finish. Unlike most other commonly plated metals, zinc protects the substrate by sacrificing itself and thus corrodes before the base metal. For corrosion protection, chromates are applied over the zinc. Chromates are chemical conversion coatings. The substrate metal participates in the coating reaction and becomes a component of the coating. The collaboration has a profound effect on the properties of the coating. Among the metals commonly chromated are zinc, zinc die casting, steel, aluminum, and sometimes copper and silver. Chromate films are typically very thin, on the order of .0000001" and contribute no measurable thickness to the overall coating.

NBP offers the following finishes over the Zinc Plate
(Their resistance to white corrosion)
Clear - (8 to 12 hours) It has a slightly iridescent blue appearance.
Black- (48 hours)
Yellow - (in excess of 96 hours) Excellent paint base.
Black- (Molybdate)
Olive Drab- (150 hours to white corrosion) dark green finish
Seals are offered for after chromates to increase corrosion resistance.