ã€China Aluminum Industry Network】 After preparatory tasks for plating on aluminum products are completed, it is possible to enter the aluminum plating process. No matter which kind of pre-treatment method is used, the first step to enter the electroplating after the completion of the pre-treatment is flash copper plating. (01) Flash copper is currently suitable for use as a flash copper plating bath, and is primarily a cyanide copper plating process. Cuprous cyanide 40g/L Temperature Room temperature Cyanide 50g/L Impulse current density 2.6A/dm2 Sodium carbonate 30g/L Time 2min Potassium sodium tartrate 60g/L Normal operating current density l. 3A/dm2 pH 10.2 to 10.5 for 3 minutes After flash copper plating is completed, it must be thoroughly cleaned and activated. Activated with 1% to 3% sulfuric acid solution. If the subsequent electroplating is acid copper plating or nickel plating, it can be directly slotted after activation without washing with water. plating. If it is plating other alkaline plating solution, especially cyanide plating solution, it must be washed after two times before plating. (02) In the future, flash plating of copper in the middle plating layer shall be carried out in accordance with the requirements of product design or process. In practice, the center plating layer may also be referred to as the bottom plating layer. The flash copper plating is only for the purpose of ensuring the dispersion and connection force of the center plating. The acceptance of a technical coating, to reach the product of the plating requirements, according to the appearance of the final coating to choose the center coating. For example, copper plating, dark nickel plating or other plating or process that can be used as a center or bottom plating. If the outer coating is silver-plated, it is more appropriate to thicken the plating after flash copper plating, for example, using acidic bright copper plating, and it must be flash-plated with silver (or electroless silver plating) before entering the outer finish plating. Plating. In the general process introduced in this chapter, copper, nickel, and other processes can be used as the center coating on aluminum plating. (03) Exterior coating The outer coating is also a desired coating for plating on aluminum, so the decorative coating can also be used for functional coating. With respect to electroplating, most of the electroplating on aluminum is a functional coating, and a small number of exterior parts have utility and decorative effects. Pure decorative plating is limited to handles, knobs, signs, etc. on the frame.
