Zinc alloy die castings are usually used in the periphery of electronics and electrical appliances. Therefore, excellent appearance and good corrosion resistance are an important and necessary feature. The surface treatment of zinc alloy generally has the following treatment methods
1. Electroplating
Electroplating has a good effect on improving the appearance, density and corrosion resistance of zinc alloy products. The most commonly used electroplating is nickel, tin, copper, silver, gold. The finished zinc alloy die-casting parts should be checked before electroplating, whether the surface of the product is of good quality, whether there are loose, cracks, porosity, air bubbles, cold lines, pinholes and other defects. Otherwise it is not suitable for electroplating.
The process of other product processing, such as polishing and grinding, needs to be processed before electroplating, so the product design and mold design should be designed with a uniform shape. Try to avoid disparate unevenness, large flat surfaces and sharp corners to make the product easier to polish. .
2. Painted
Lacquering can be used for decorations, protection, and signs. Painting can also hide some of the surface defects of zinc alloy die castings, making the product surface more textured. In this process, the concentration and spraying amount of paint must strictly abide by the operating specifications to avoid the occurrence of orange peel, pinholes, dumb color, oil accumulation, oil rejection, etc.
3. Chemical film formation
Chromate treatment can improve the corrosion resistance of zinc alloy products and increase the appearance of the product surface. A protective film is formed on the surface of the product to make zinc alloy castings easier to paint and color.
4. Electrostatic spraying
Electrostatic spraying can also form a protective film for zinc alloy castings, making the surface of the casting smoother, more beautiful, and more textured. And improve corrosion resistance.
Electrostatic spraying must also strictly abide by the work requirements. Before spraying, check whether the equipment is operating normally, and select the best cage position for the product, adjust the walking speed of the casting, and be strict with temperature, oil viscosity and oil volume. Control to ensure that every casting can be evenly and completely sprayed with oil.
