Cadmium Plating (Electroplating)

New Method Plating Company, Inc. is one of the finest specialty platers in New England. We offer nickel, zinc, chrome, copper, and cadmium plating to enhance the properties of diverse components. Here, learn more about our capabilities with cadmium plating specifically, and the many benefits and applications of the process.

Cadmium Plating Explained

Cadmium plating is an electroplating method through which manufacturers apply cadmium to the surface of a substrate material in a thin layer. The substrate is typically another metal, with common choices being iron and steel. The goal is to improve the surface properties and resiliency of plated components, making the process a popular option for enhancing products across diverse industries. It’s particularly well-known for its ability to improve solderability as well as resistance to wear and corrosion.

Types of Cadmium Plating (Electroplating)

At New Method Plating, we utilize a cyanide-based electrolyte solution for our cadmium plating. While such solutions are toxic, our team is experienced in safely working with and disposing of cyanide plating baths. This electroplating technique, cyanide cadmium plating, achieves a smooth, bright surface finish on a substrate while simultaneously giving it exceptional corrosion resistance.

Cadmium plating is classified into types I through III, depending on its coloring post-treatment. Type I, or “as plated,” is cadmium plating’s natural coloring, or its appearance without undergoing any color treatments. Iridescent yellow in color, type ll is a supplementary chromate treatment. After a period of 96 hours in a 20% salt spray solution, type II cadmium plating should not expose white corrosion cadmium products, basis metal corrosion products, or pitting.

AMS QQ-P-416 is a critical standard in the aerospace industry for cadmium plating. The standard categorizes cadmium plating into distinct types and classes, each with defined requirements concerning plating thickness, the strength of its adhesion, and its final appearance. The various classes of cadmium plating and the associated thickness of coating are:

Class 1: Minimum coating thickness of 0.0005″
Class 2: Minimum coating thickness of 0.0003″
Class 3: Minimum coating thickness of 0.0002″

Benefits of Cadmium Plating

The key advantages cadmium plating will lend to your next project include:

01Excellent lubricity and a low coefficient of friction

Lubricity properties are inherent to cadmium. This and a low coefficient of friction allow cadmium plating to minimize wear for moving components, ultimately enhancing their performance. These qualities make the process particularly useful for threaded fasteners and other sliding or movable parts.

02Enhanced wear resistance

In mechanical applications, the impressive durability of cadmium coatings also allows electroplated parts to endure wear and tear.

03Superior corrosion resistance

Cadmium develops an oxide layer on its surface that offers a substrate protection from corrosion in harsh environments. Corroding preferentially as compared to steel or another base metal variety, cadmium plating provides what's called sacrificial protection — even if the cadmium coating sustains damage. This is particularly useful for components with marine applications or those with exposure to alkalis.

04Low electrical contact resistance

Beneficial for electrical components like connectors, this plating features low contact resistance and great conductivity.

05Good throwing power

The electroplating process offers good "throwing power," evenly depositing cadmium on part surfaces regardless of part profile complexity or recessed areas in the design.

06Exceptional solderability

Surfaces with cadmium plating are easy to solder, making the process beneficial in electrical and electronic assemblies and applications.

Industries and Applications

New Method Plating provides cadmium plating services for numerous key industries.

Aerospace
Aerospace
Aerospace is the primary industry using cadmium-plated parts in today’s market. The industry relies on durable components that will maintain their integrity in the face of high heat and corrosive substances. The plating material’s natural lubricity and electrical conductivity add to its popularity for mission-critical aerospace products such as:
- Control systems
- Electrical connectors
- Landing gear
- Screws and various fasteners
- Wrenches
Communications Equipment
Communications Equipment
Cadmium plating is useful in the communications sector for protecting parts and equipment that undergo frequent exposure to everything from saltwater and corrosive chemicals to extreme thermal conditions. You might use such cadmium-plated communications system components as:
- Chassis
- Connectors
- Relays
Marine
Marine
Components for the marine industry must be able to withstand saltwater exposure. Cadmium plating provides excellent corrosion resistance properties, making it an ideal solution for the following:
- Offshore platforms for oil and gas operations
- Marine fasteners and hardware
- Shipbuilding applications
Military and Defense
Military and Defense
For handling rugged applications in harsh environments, the military and defense sector is another industry that depends on cadmium plating to ensure parts and products maintain their performance. The electroplating process is common for the following applications:
- Bonding components to aluminum aircraft frames
- Military vehicle parts like hoses, disc brakes, and door handles
- Weaponry systems
Nuclear Power
Nuclear Power
Cadmium effectively absorbs neutrons, making plating of this material well-suited to nuclear power applications. Examples in this market include:
- Nuclear reactor control rods
- Shielding products
Electronics (Limited)
Electronics (Limited)
Cadmium plating isn’t used as frequently today in the electronics sector, but you may see the process utilized for specialized applications with:
- Connectors
- Hardware
- Laptop and cellphone batteries
- Relays
- Switches

Cadmium Plating Process

To achieve the benefits that cadmium plating offers, components must first go through a multi-step process.

Surface Preparation

Cleaning. The electroplating process begins with a thorough cleaning of the substrate’s surface using methods such as abrasive blasting, acid pickling, or alkaline cleaning. This process step effectively eliminates surface contaminants like dirt, rust, and grease.
Rinsing. Next, we use water to rinse the parts, washing away any remnants of the cleaning agent.

Plating Bath

Bath Composition. We’ll make up a cadmium plating bath of cadmium oxide and sodium cyanide. These baths are typically a combination of cadmium metal ions, controlling additives, and complexing agents.
Electroplating. We connect the substrate to a DC power supply’s cathode, the negative terminal, and immerse that substrate into the prepared plating bath. The positive terminal is adjoined with a cadmium anode. Once electrical current begins to flow, the cadmium ions reduce and the process deposits the thin cadmium coating onto the part surface.
Plating Thickness. The current density and plating time are factors responsible for the cadmium layer’s thickness.

Post-Treatment

Cleaning. We again rinse the plated parts with water, removing any residual plating solution.
Chromate Conversion Coating. This post-treatment process immerses plated components into a chromate solution. An optional step, chromate conversion coating enhances both form and function, achieving a decorative surface finish on a part while improving its resistance to corrosion.
Drying. To efficiently dry coated parts, we’ll utilize hot air or similar drying techniques.

Inspection

Visual Inspection. Plated parts undergo a visual inspection so we can check for uneven coating thickness and pits, blisters, or other surface defects.
Thickness Measurement. Finally, our team utilizes magnetic induction or X-ray fluorescence to measure the thickness of the plating and ensure your parts receive optimal surface protection.