Electrodeposited Cadmium Plating
Electroless cadmium finishing is a full-bodied and adaptable metallic coating. RoHS compliant cadmium is a soft white metal that, when plated onto steel, cast iron, malleable iron, copper, and powdered metal, functions as a "sacrificial coating," corroding before the substrate material. To augment the corrosion protection of cadmium plating, chromate conversion coatings can be applied over the plated metal, which allows shades from gold and bronze to forest green and olive drab, Olive drab cadmium plating is most popular for military applications, though the process in general is used in a wide range of industries and applications.
Cadmium Plating Benefits
Since cadmium finishing is used in a broad range of industrial applications it has many outstanding benefits that make it a highly sought-after RoHS compliant finish. Some of the direct benefits of electroless cadmium, include:
- Good corrosion resistance
- Low galvanic corrosion in contact with aluminum
- Exceptional white luster similar to silver plating
- Excellent Lubricity
- Cathodic protection of steel
- Low electrical contact resistance
- Good solderability
Additionally, electroless cadmium plated steel products may require heat treating for optimal surface hardness and finish. Common heat treating for cadmium plating includes a 23-hour hydrogen embrittlement relief bake at 500-750°F. We have all the necessary equipment for our heat treating processes in-house, allowing us to monitor them closely for proper performance.
Cadmium Finishing Applications
Cadmium plating offers an exceptional bonding surface for adhesives, such as those increasingly used in aircraft manufacturing, and is the preferred coating for salt-water environments. Additional advantages of cadmium plating include: low electrical resistance; outstanding conductivity; superior solderability; favorable galvanic coupling with aluminum; and excellent natural lubricity, which results in prevention of galling and a low coefficient of friction. Due to these exceptional benefits cadmium plating is used for a wide range of industrial applications, including:
- Aircraft manufacturing
- Salt-water environment coatings
- Aircraft maintenance
- Helicopter parts
- Flight component corrosion protection
- Disc brake components
- Electrical connectors
Electroless Cadmium Specifications
Our cadmium platings meet numerous Mil-Spec standards including: FED QQ-P-416F, ASTM B766-86, and SAE/AMS 2400 standards. Constant monitoring and frequent testing of our chemistries helps us maintain optimum quality. Some of the other applicable specifications, include:
- ASTM A165
- ASTM B766
- ISO 4521
- SAE AMS 2400
- SAE AMS 2401
- PN 13.08 (UTC Aerospace Systems/Hamilton Sundstrand)
- M-032-P (Mercury Marine)
- Most Major OEM Specifications
Cadmium vs Nickel & Zinc
A large amount of hardware that can be found around the world is zinc plated. However, there is no direct substitute for cadmium plating, since cadmium offers sacrificial protection as well as a bevy of other benefits that nickel or zinc do not offer. Many parts will be fine with standard nickel or zinc plating, but certain applications require the direct benefits that cadmium plating can provide.
In addition, there is no exact equivalent of cadmium. If your application will not accept cadmium you will need to decide what beneficial properties your new material must exhibit. Zinc and cadmium have similar but not equal corrosion resistances. One is better in industrial settings and the other is better in maritime settings. Nickel offers better corrosion resistance but has far less lubricity and is not as malleable.
Contact ENS Technology Today
Contact us for more information regarding the benefits of RoHS compliant cadmium plating, or request a quote today.