Discussion on post-processing technology of zinc alloy die casting

After die-casting, the post-processing process of zinc alloy die casting plays a vital role in its final performance and appearance.

1. Mechanical processing post-processing

Polishing

Mechanical polishing is a common method. By using sandpaper or polishing wheels of different particle sizes, the surface of the product is polished gradually from coarse to fine. Coarse polishing can quickly remove more obvious defects such as parting lines and gate marks generated during the die-casting process; fine polishing can make the surface of the product as bright as a mirror, improve the beauty of the product, and is suitable for products such as decorations and precision instrument shells that have high requirements for appearance.

Grinding

Grinding is mainly to correct the dimensional accuracy of the product. During the die-casting process, due to mold wear or some deviations in the die-casting process, the size of the product may have a certain error. Grinding can accurately remove a small amount of material so that the product reaches the size required by the design, and it can also improve the surface roughness.

2. Surface treatment

Electroplating

Electroplating is to plate a layer of metal film on the surface of zinc alloy die casting, such as chrome plating, nickel plating, etc. Chrome plating can improve the corrosion resistance of the product, and make the surface of the product have a metallic luster and a more beautiful appearance; nickel plating can not only improve corrosion resistance, but also increase the hardness of the product surface. However, before electroplating, the product needs to be strictly cleaned and activated to ensure the adhesion of the electroplating layer.

Chemical conversion film treatment

This treatment method is to form a protective film on the surface of the product through chemical reaction, such as passivation treatment. The passivation film can effectively prevent the corrosion of the zinc alloy surface and improve the weather resistance of the product. It is relatively simple to operate and has low cost. It is widely used in some zinc alloy die castings that do not have particularly high requirements for appearance but have certain requirements for corrosion resistance.

Through the reasonable application of these post-treatment processes, the appearance and performance of zinc alloy die casting can be significantly improved, thereby expanding its application range and improving the market competitiveness of the product.