Chromium plating is a metal surface treatment technology that forms a chromium coating on a metal surface by electrochemical deposition to increase the wear resistance, corrosion resistance or provide a decorative effect on metal parts. Chrome plating is divided into two main categories: decorative chrome plating and hard chrome plating.
Author: Anna
Chromium plating is a metal surface treatment technology that forms a chromium coating on a metal surface by electrochemical deposition to increase the wear resistance, corrosion resistance or provide a decorative effect on metal parts. Chrome plating is divided into two main categories: decorative chrome plating and hard chrome plating.
Decorative Chrome Plating (Bright Chrome Plating)
Bright Chrome Plating is mainly used for aesthetic and rust prevention purposes. The plating layer is usually very thin, about 0.25 to 0.5 micron, and the surface of the plating layer is very smooth and has a mirror-like luster. Decorative chrome plating is commonly used for automotive parts, hardware, bathroom accessories, etc.
Hard Chrome Plating
Hard Chrome Plating is designed to improve the hardness and wear resistance of metal parts, with a thicker layer, ranging from a few microns to several hundred microns. Hard Chrome Plating is widely used in tools, molds, bearings, piston rods and other parts that need to withstand high friction and wear.
Chrome plating process flow:
Pretreatment: Clean the metal substrate, remove grease, rust and oxidized layer to ensure good adhesion of the plated layer.
Activation: Activate the metal surface to improve its electrical conductivity and the adhesion of the plated layer.
Electroplating: The metal part is used as the cathode, put into the electrolyte containing chromic acid and sulfuric acid, and energized with direct current, so that the chromium ions are reduced to metallic chromium on the cathode and deposited on the surface of the metal part.
Post-treatment: The plated parts are cleaned to remove residual electrolyte and sometimes passivated to improve the corrosion resistance of the coating.
Key parameters are controlled:
Current density: determines the deposition rate and microstructure of the plated layer.
Temperature: affects the viscosity and conductivity of the plating solution, which in turn affects the quality of the coating.
pH value: needs to be kept within a certain range to maintain the stability of the plating solution.
Concentration of the plating solution: affects the growth rate and quality of the plated layer.
Areas of application:
Automobile industry: used for body trims, wheels, etc.
Machinery manufacturing: used to improve the wear resistance and corrosion resistance of parts.
Home decoration: used for furniture, faucets, etc. to provide a beautiful surface.
Chromium plating technology is constantly evolving, and as environmental requirements increase, traditional hexavalent chromium plating solutions are gradually being replaced by trivalent chromium plating solutions or other more environmentally friendly technologies to minimize the impact on the environment.