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What is Die Casting? Its Characteristics And Precautions

Die casting is a casting technique, also known as die casting. Die casting is the process of injecting melted non-ferrous metals into molds to form various shapes. Die cast parts are widely used in many products such as automobiles, home appliances, copiers, sewing machines, etc.  

What is die casting? Main features and drawing markings

Die casting is the process of melting non-ferrous metals and then applying pressure to inject them into a mold. Due to the use of molds, it is suitable for mass production. Unlike other castings, the characteristic of die-casting is that it requires pressure, resulting in good dimensional accuracy. In addition, because a mold is used instead of a sand mold, the surface is also relatively smooth. Die casting is suitable for manufacturing complex shaped products that cannot be achieved with sheet metal parts, or products that cannot be processed with resin. Due to its ability to create complex three-dimensional shapes, it is characterized by higher degrees of freedom than sheet metal parts and higher yield than cutting processing. On the other hand, it cannot be used to manufacture pipes or hollow shapes. In addition, due to the use of molds, it is not suitable for shapes that protrude inward, such as cantilever or side holes. Die casting is suitable for materials such as aluminum alloy, zinc alloy, magnesium alloy, copper, etc. Especially aluminum die casting and zinc die casting are widely used. On the drawing, aluminum die castings are marked as ADC, and zinc die castings are marked as ZDC.

Characteristics of Aluminum Die Casting and Zinc Die Casting

The characteristics of aluminum die castings are light weight, stronger than zinc die castings, and small dimensional changes over time. Therefore, it is used in the manufacturing of many components, such as the casing of a car gearbox. In addition, utilizing its good thermal conductivity, it is also used as a heat dissipation plate. Zinc die-casting is heavier than aluminum die-casting and has no advantage in strength. But its machinability is very strong, and it can manufacture parts that are more complex and have higher precision than aluminum die castings. Generally used for manufacturing fine parts that do not require too much strength. It is also frequently used in the structural parts of automotive components and industrial machinery. In addition, due to its easy surface treatment, it is also used for furniture handles, etc. Although the dimensional accuracy of die-casting parts is relatively high, compared with cutting and other processes, the dimensional accuracy is not high. Therefore, mechanical processing such as cutting and grinding is usually required before assembly at the mating surfaces of die-casting parts, installation parts of other components, and fastening surfaces of screws.

Precautions for using die-casting

Although die-casting has good mass production and is easy to manufacture complex shapes, it also has its drawbacks.

The main disadvantages of die-casting are as follows.

Compared to cutting, the same material has lower strength

When injecting molten metal under pressure, there is a problem of decreased strength in aluminum and zinc materials compared to parts made by cutting processes due to the mixing of air and other issues. Injecting metal liquid in the vacuum state of the mold can perfectly improve this deficiency, but it requires a higher cost.

High upfront costs

Die casting requires the use of molds. In addition, molten metal needs to be injected, and the production equipment used for processing is quite expensive. Therefore, if there is no large-scale production demand like in the case of automobiles, it may not be possible to recover the initial investment costs.

Summary

Aluminum die-casting and zinc die-casting are mainly used in the die-casting process. Aluminum die castings have the characteristics of light weight, strong strength, and easy heat transfer. The characteristics of zinc die-casting are good processing performance and high dimensional accuracy. Please choose a reasonable processing method based on their respective characteristics.