Among them, the composition of electroplating solution varies from plating layer to plating layer, but all of them contain main salt providing metal ions, complexing agent complexing with the metal ions in the main salt to form a complex, buffer for stabilizing the pH value of the solution, anode activator and special additives (such as brightener, grain refiner, leveler, wetting agent, stress eliminator and fog suppressant).
Electroplating is a process in which metal ions in plating solution are reduced to metal atoms by electrode reaction under the action of external electric field, and metal deposition is carried out on the cathode.
Therefore, this is a metal electrodeposition process including liquid phase mass transfer, electrochemical reaction and electrocrystallization.
Extended data
Electroplating is divided into hanging plating, barrel plating, continuous plating and brush plating, which is mainly related to the size and batch of the plated parts.
1, hanging plating is suitable for products of general size, such as bumpers of automobiles and handlebars of bicycles.
2, barrel plating is suitable for small pieces, fasteners, washers, pins, etc. Continuous electroplating is suitable for large-scale production of wire and strip.
3. Brush plating is suitable for local electroplating or repair. The electroplating solution includes acidic, alkaline, acidic and neutral chromium-containing mixed solutions. No matter what electroplating method is used, electroplating bath, hanger, etc. Contact with the product to be plated and the plating solution should be universal to some extent.
Single metal electroplating has a history of 170 years, and 33 metals in the periodic table can be prepared by electrodeposition from aqueous solution. There are 10 kinds of zinc plating, nickel, chromium, copper, tin, iron, cobalt, cadmium, lead, gold and silver.
A coating formed by simultaneously depositing two or more elements on a cathode is an alloy coating. The alloy coating has the organizational structure and properties that a single metal coating does not have, such as amorphous Ni-P alloy, sn alloy with each core not found in the phase diagram, and alloy coating with special decorative appearance, especially high corrosion resistance, excellent weldability and magnetism.
Baidu Encyclopedia-Electroplating (Process)