Electroplating surface treatment of Zinc Die Casting is very important. If electroplating is not done well, all the work in the early stage is wasted, so we must pay attention to the electroplating of products. What factors affect the electroplating quality?
1. To select raw materials for zinc die casting, regular national standard materials must be selected for die casting.
2. The design of zinc die casting should be reasonable, and the shape of die castings should consider the masking ability of electroplating, and try to reduce the number of blind holes, so that it is difficult to carry solution with water washing. Cut sharp corners and other parts, so that the power lines are evenly distributed during electroplating.
3. The die casting process and die design are reasonable, so that the die casting will not suffer from shrinkage cavity, pinhole and looseness, which will directly affect the adhesion of the coating.
4. In the production process of zinc die casting, try to reduce segregation. If aluminum segregates in some parts, aluminum will dissolve first during degreasing, and pores and pinholes will occur on the outer surface of die castings and cannot be cleaned, resulting in poor bonding force, resulting in peeling and blistering of the coating.
5. During grinding and polishing, attention should be paid to master the scale. The fine layer of 0.05 ~ 0.1 mm formed during cooling of die casting surface is very important for electroplating. When grinding and polishing, the loss of fine layer should be reduced as much as possible. If this layer is ground and thrown away, the exposed porous structure will be obtained, and a good electroplating layer will not be obtained on this layer.
6. The copper-nickel-chromium plating layer, which is composed of many kinds of plating, is a negative plating layer relative to the substrate. As long as the mechanical maintenance effect is achieved, the zinc die casting will corrode in humid air, so it is necessary to ensure that the plating layer has no holes, otherwise the corrosion products will make the plating layer blister.
7. The residue of die casting during die casting and machining should be cleaned as much as possible after machining. As the residue is a vivid metal, it will react with the solution in any electroplating process, which will damage the plating solution and affect the electroplating quality.
