The Advantages of Gravity Die Casting and the Difference from High Pressure Die Casting

Gravity die casting is used to manufacture cast parts from non-ferrous materials such as aluminum or low-temperature alloys. Gravity die casting, sometimes called permanent die casting, is a method of casting high-quality parts in a range of low-temperature metals. Unlike pressure die casting such as squeeze die casting, gravity die casting involves simply pouring molten metal into a mold without applying any additional force. Also, unlike pressure die casting, gravity die casting can use both metal and sand cores, known as semi-permanent die casting, for greater design complexity.

1. Advantages of gravity die casting

Different from silica sol casting, one of the advantages of the gravity die casting process is that it can produce high-quality castings with complex shapes, while still maintaining excellent mechanical properties such as strength. This makes it ideal for making aluminum castings that cannot be met by die-casting processes.

Advantages of gravity die casting include: Suitable for small and large batches of parts. For larger, thicker parts that cannot be produced by the die-casting process. Compared with the die-casting process, the mold investment is less. The surface of the parts produced is much smoother than the sand casting method. To produce parts with excellent mechanical properties, T6 heat treatment can also be applied to improve performance. Few size constraints and complex shapes can be achieved. For products with hollow areas, sand cores can be placed in the mold. As you may have interest, we also offer information about vacuum die casting process.

2. How does gravity die casting compare with high-pressure die casting?

As a China stainless steel investment casting company, in the high-pressure die-casting process, a steel mold is first created to form a cavity of the same shape as the desired part, and then liquid metal is pressed into the mold under high pressure. The injected metal then solidifies rapidly in the mold, and after solidification, the solid metal part is removed from the mold. When the metal cools, excess material is removed and the net shape product is complete. Repeat this process to produce the part with the ordered quantity.

Compared to high-pressure die casting, there are several differences between the two casting methods: Because gravity dies casting uses gravity to pour the metal, while high-pressure die casting relies on high pressure, gravity die casting is slightly less strong than high-pressure die casting. The mold material of high-pressure die casting is tool steel, so the mold cost of high-pressure die casting is much higher than that of gravity die casting. Therefore, if the volume is small, gravity dies casting is preferred. For parts with small wall thickness, high-pressure die casting works better because gravity die casting is prone to casting defects. For aluminum alloys, gravity die casting usually uses A356 as the casting alloy, while A380 is more widely used in the high-pressure die-casting process. 

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