Cadmium plating is a surface treatment process mainly used to improve the corrosion resistance and sliding properties of metal parts, especially in salt water environments.
Author: Anna
Cadmium plating is a surface treatment process mainly used to improve the corrosion resistance and sliding properties of metal parts, especially in salt water environments. Cadmium plating has good corrosion resistance and can effectively protect the base metal from environmental erosion, especially in marine and high humidity conditions. In addition, cadmium plating has a low coefficient of friction, which makes it ideal for bearings, threaded joints and other mechanical parts that require reduced friction.
The process for cadmium plating typically includes the following steps:
Pre-treatment: Prior to plating, the workpiece needs to be thoroughly cleaned and pre-treated to remove grease, oxides and other impurities to ensure a good bond between the plating and the substrate. Pretreatment may include steps such as degreasing, pickling, and activation.
Electroplating: The cleaned workpiece is placed into an electrolyte solution containing cadmium ions as the cathode and cadmium metal as the anode. When current is passed through the electrolyte, cadmium ions are reduced on the cathode and deposited on the surface of the workpiece, forming a cadmium plating layer.
Post-treatment: After plating, the workpiece is cleaned to remove residual electrolyte and then dried. In some cases, passivation is applied to form a protective film to further enhance corrosion resistance.
Some of the key characteristics of cadmium plating include:
Corrosion resistance: Cadmium plating is highly resistant to salt spray and seawater, making it suitable for applications in harsh environments.
Low coefficient of friction: Cadmium plating has a low coefficient of friction, which helps to minimize wear between moving parts.
Conductivity: Cadmium plating maintains good electrical conductivity and is suitable for parts that require electrical contact.
Controlled thickness: The plating process allows for precise control of the thickness of the plated layer to meet different application requirements.
Despite the above advantages of cadmium plating, cadmium itself is a toxic heavy metal that is potentially harmful to the environment and human health. As a result, many countries and regions have restricted or banned the use of cadmium, especially in consumer products. In order to comply with environmental regulations, many industries have turned to other alternative platings such as zinc-nickel alloys and trivalent chromium plating, which to a certain extent can provide similar protective effects while reducing the impact on the environment.