Die Casting is popular method in the manufacturing process. It is used to produce metal parts. The molten metal is forced into the mold cavity under high pressure.

The two common methods of die casting are gravity die casting and pressure die casting. Each of this process has its own advantage and is suitable for different applications.

Here is a detailed comparison of the two-

What is gravity die casting?

Also, known as permanent mold casting, gravity die casting is the process where molten metal is poured into a mold using gravity. The process does not rely on high-pressure methods and thus it is simple and more cost-effective method for certain projects.

also read: What is Aluminum casting?

What is pressure die casting?

Pressure die casting involves injecting molten metal into the mold under high pressure which is maintained until the casting solidifies. The method is faster and more suitable for high-volume production.

What is the difference between gravity die casting and pressure die casting?

• Gravity die casting relies on gravity to fill the mold; the process is thus slower and is less suited to long production runs. The pressure die casting allows the alloy to be injected quickly and is coupled with the highly automated nature of the process and high productivity can be achieved while the potential of human error is reduced.

• Pressure die casting molds need to be made from hardened steel and will often require internal cooling channels to dissipate heat quickly. Gravity die casting molds can be made from cast iron and the lower cycling rates prevent heat build-up in the mold allowing rapid chilling of the casting. Also, sand sores can be used in gravity die casting to create internal voids that are not possible with pressure die casting.

• Pressure die casting can achieve complex shapes and fine details which might not be possible with gravity die casting.

• The slow pouring method in gravity die casting allows for excellent surface finish and dimensional accuracy making it suitable for aesthetic parts requiring minimal machining after casting. Pressure die casting can achieve complex shapes and fine details easily.

How to choose the right process – Gravity die casting v/s Pressure Die casting?

• Volume of production: For low to medium volumes gravity die casting might be more economical and for high volume production, pressure die casting is good to go with.

• Complexity of the parts: If the part requires intricate details and tight tolerances, pressure die casting is preferred.

• Properties of materials: Both methods are used with non-ferrous metals, but the choice many depend on specific properties required in the finished part like weight, strength, or corrosion resistance.

• Cost: Gravity die casting is a better choice for small budget or where equipment cost is to be minimized.

In a nutshell, both gravity die casting and pressure die casting have unique advantages. Manufacturers need to carefully consider these factors to choose the most appropriate method that ensures efficiency, quality and profitability.

FAQs

1. What is gravity die casting?
   It is the manufacturing process where molten metal is poured into a mold using gravity without using high pressure.
2. What is pressure die casting?
   It is a manufacturing process where molten metal is injected into a mold cavity under high pressure.
3. How to choose between gravity die casting v/s pressure die casting?
   When choosing between gravity die casting v/s pressure die casting, consider production volume, part complexity, material properties and cost.