The electroplating surface treatment of zinc die casting is very important. If the electroplating is not done well, all the work in the early stage is wasted. Therefore, we must pay attention to the electroplating process of the product. The electroplating quality is affected by those factors. Let's have a look together.
1. In the selection of raw materials for zinc die casting parts, we must choose good materials for die-casting.
2. The design of zinc die casting parts should be reasonable, and the shape of die casting parts should consider the ability of electroplating, and try to reduce non-through holes in order to prevent carrying solution in water washing process. Cut sharp corners and other parts to make the power lines evenly distributed during electroplating.
3. In the production process of zinc die castings, try to reduce the segregation phenomenon. For example, aluminum segregation in certain parts, if aluminum is not first dissolved during degreasing, pores and pinholes will be generated on the surface of the die casting and cannot be cleaned. This will result in a lack of binding force, and it will cause peeling and blistering on the coating.
4. We need to pay attention during the grinding and polishing process. The 0.05-0.1mm fine layer formed during the surface cooling of the zinc die casting is very important for electroplating. When grinding and polishing, the loss of the fine layer should be reduced as much as possible. If this layer is ground and thrown away, porous structure will be revealed, and you can not get good electroplating layer on this layer.
5. The copper-nickel-chromium electroplating layer composed of multiple plating types is a negative plating layer relative to the substrate. It only has the mechanical maintenance effect. The zinc die casting is easy to get corroded in the humid air, so it is necessary to ensure that the plating layer doesn't has any holes. Otherwise, the corrosion of the zinc alloy will cause blistering of the coating. Compared with steel parts, the coating of zinc die castings should be thicker.
6. Residues of zinc die castings during die casting and machining should be cleaned as much as possible after processing. Since the residue is a vivid metal, in any process of electroplating, it will react with the solution and damage the plating solution, which will affect the quality of electroplating.