Once the plating pre-treatment preparation is complete, the aluminum plating process begins to be implemented. Regardless of which pretreatment method is chosen, the first sequence of work into plating after we complete the pretreatment is flash copper plating. Let's take a look at three plating techniques for industrial aluminum profiles.
Ⅰ, Flash copper plating
1. After the end of flash copper plating, it needs to be fully cleaned and activated. Activation needs 1%~3% sulfuric acid solution. If the future plating is acid copper or nickel plating, activation can be directly into the tank plating without water cleaning.
2. If it is plating solution or other alkaline plating solution, especially cyanide plating solution, it must be cleaned twice after activation before entering the tank for plating.
Ⅱ, The center plating
1. After flash copper plating, the center plating layer should be plated according to the commodity plan or skill requirements. In practice, the center plating layer can also be said to be the bottom plating layer. Flash copper plating just to ensure that the loose talent and connectivity and accept the skill plating. In order to satisfy the requirements of plating for merchandise, the center plating layer should be choosed according to the appearance of the plating.
2. For example, acid copper plating. Deep nickel plating or other plating or skill that can be used as center or bottom plating. Assuming that the surface plating is silver plating, the plating should be appropriately thickened after flash copper plating, such as acid bright copper plating, which must be flash silver plated (or chemically silver plated) before entering the surface plating. After all, among the general skills cited in this chapter, skills such as copper and nickel plating can be used as the center plating for aluminum plating.
Ⅲ, Surface plating
1. the external surface plating is aluminum plating required for the intention of the plating, so decorative plating, but also functional plating.
2. for electronic plating, plating on aluminum is mostly functional plating, and then a small amount of external decoration can also achieve decorative effect. Pure decorative plating is limited to handles, knobs and logos on the outer frame.
Ⅳ, Classification and selection of plating use conditions
From the point of view of anti-corrosion requirements, the design of the surface treatment should be considered as follows:
1) Precious metals (gold, platinum), stainless steel containing chromium in more than 18%, magnetic alloy materials, and nickel-copper alloys, etc., generally do not need to add a protective layer.
2) Carbon steel, low alloy steel and cast iron are susceptible to corrosion in the atmosphere and should be protected with a protective layer.
3) Copper and copper alloys are protected by bright pickling, passivation, electroplating or painting according to different conditions of use. Phosphor bronze or beryllium bronze precision parts can be manufactured without surface treatment.
4) Aluminum and aluminum alloy can be anodized and closed. Small parts not suitable for anodizing can be treated with chemical oxidation. Casting aluminum alloy can be painted protection.
5) Zinc alloy can be protected by phosphating, passivation, electroplating or painting.
