Electrolytic chromium plating is one of the widely used techniques for metal surface treatment. Electrolytic chromium plating involves the deposition of a thin layer of chromium on a metal surface, usually done through an electroplating process. The chromium layer provides various advantages such as wear resistance, corrosion resistance and improved mechanical and electrical properties. The process of electroplating also provides a wide range of decorative finishes.
The process of electrolytic chromium plating involves the use of an electrolytic cell, a cathode, an anode and a solution containing chromium ions. The cathode is a metal substrate, that can be either iron, steel or brass. The anode is a non-metallic carbon or graphite piece, with a diameter smaller than the diameter of the cathode.
The electrolyte solution used for chromium plating consists of chemical reagents and chromic acid at a precise concentration and combined with distilled water and other auxiliaries. During the process the anode of the cell releases the chromic acid, while the cathode releases the metal ions into the electrolyte solution. The chemical reaction between the chromic acid and the metal ions, results in a thin film of chromium on the surface of the metal substrate.
The electrolytic process is carried out at a moderate temperature, as higher temperatures can degrade the properties of the chromium layer. During the plating process, the current density, gap between the cathode and anode, and electrolyte concentration needs to be carefully monitored and controlled to ensure that the plating process is carried out in an optimal manner.
After the chromium plating process is completed the part is usually flushed with distilled water to remove any surface contaminants and the chromium layer is then passivated to protect the surface from further oxidation.
Electrolytic chromium plating has become a common method for metal surface treatment, offering various advantages such as corrosion and wear resistance, improved mechanical and electrical properties and decorative finish. The process of chromium plating involves the use of an electrolyte solution, containing chromic acid, with careful control of current density, anode gap and electrolyte concentration to ensure optimal plating. After the plating process is completed the parts are passivated to protect the surface against further oxidation.
