After die-casting, zinc alloy needs to be polished to make the surface of zinc alloy die-casting smoother, more delicate and beautiful. However, zinc alloy die-casting needs to be surface treated after polishing. If surface treatment is not performed, zinc alloy die-casting will gradually be oxidized, and the original smooth and delicate luster of zinc alloy will be lost. There are three common methods for surface treatment of zinc alloy: electroplating, metal spraying, and painting.
Electroplating surface treatment of zinc alloy die-casting is one of the most commonly used zinc alloy treatment processes. The zinc alloy electroplating process is to plate nickel on the copper base layer and then treat it with chromium. In addition, zinc alloy castings can also be directly chromium-plated to improve the hardness and wear resistance of the castings, reduce the friction factor and improve corrosion resistance
Metal spraying surface treatment of zinc alloy die-casting is to apply a very thin metal film on the surface of the treated parts under high vacuum. Metal spraying treatment of zinc alloy die-casting can simulate the appearance of copper, silver, brass, gold, etc. This process is mostly used for die-casting. If the surface defects can be concealed by applying primer after degreasing, the workpiece to be processed does not need to be polished. After low-temperature baking, aluminum vapor is deposited on the parts under vacuum to form a thin film. After the second spraying of varnish, it is baked to obtain a silver-white paint layer, which can be dyed into any color.
Zinc alloy die castings are subjected to surface painting treatment. Before painting, the workpiece is usually treated with phosphate or chromate solution. For some cheaper parts, acrylic paint with weak adhesion and acidic corrosive components can be used. For parts with high corrosion resistance requirements, epoxy resin paint or various amine-based paints are used, and baking is carried out after painting. Zinc alloys can be coated with various different paints.
Post time: Aug-28-2024