Aluminum plating process
After the pretreatment preparations for electroplating on aluminum are completed, the process of electroplating on aluminum can be entered.
Regardless of which pre-treatment method is used, the first step in electroplating after the pre-treatment is completed is flash copper plating.
(1) Flash copper
The plating solution that is currently suitable for flash copper plating is mainly the cyanide copper plating process.
After flash copper plating is completed, it should be fully cleaned and activated. A 1% to 3% sulfuric acid solution is used for activation. If the subsequent electroplating is acid copper or nickel plating, it can directly enter the tank without washing after activation plating. If it is plating other alkaline plating solution, especially cyanide plating solution, it must be washed twice after activation before it can be electroplated in the tank.
(2) Intermediate plating
After flash copper plating, the intermediate plating should be electroplated according to the product design or process requirements. In fact, the intermediate plating can also be said to be an underplating. Flash copper plating is only a technical coating used to ensure dispersion and bonding In order to meet the requirements of the product for the coating, the intermediate coating should be selected according to the surface coating. For example, acid copper plating, dark nickel plating, or other plating seeds or processes that can be used as intermediate or underplating. If the surface coating is silver-plated, it is necessary to appropriately thicken the coating after flash copper plating, for example, using acid bright copper plating, etc., and it must be flash silver (or chemical silver plating) before entering the surface coating plating. In the general process introduced in this chapter, copper, nickel and other processes can be used as the intermediate plating for aluminum plating.
(3) Surface coating
The surface plating layer is also a target plating layer required for electroplating on aluminum, and may be a decorative plating layer or a functional plating layer. For electronic plating, most of the electroplating on aluminum is a functional coating, and a small number of exterior parts have both functional and decorative functions. Pure decorative plating is limited to handles, knobs, signs, etc. on the frame.