The vacuum machine in a die casting machine reduces air entrapment and porosity, thus enhancing the quality of cast parts.

This technique involves using a vacuum system to evacuate air and gases from the die cavity before or during the injection of molten metal.

What is vacuum machine？

The Vacuum Die Casting Machine, as a specialized equipment in metal die casting, integrates a vacuum system to extract air and gases from the molten metal before injection into the mold cavity.

Thereby significantly reducing porosity and gas inclusions, and thus improving the mechanical properties, surface quality, and overall integrity of castings.

Types of Die Casting Vacuum Machines

Hot chamber vacuum die casting machines: molten metal baths are integrated with the injection system, and the vacuum draws air through the transfer tube or injection cylinder, suitable for low melting point alloys (such as zinc, magnesium).

Cold chamber vacuum die casting machine: molten metal is injected from an external crucible, and the vacuum system is directly connected to the mold cavity, suitable for high melting point alloys (e.g., aluminum, copper).

Ultra-high pressure vacuum die casting machine: A more advanced variant with a higher vacuum level (up to 1 mBar) for the production of large, thin-walled parts (e.g. automotive structural parts).

The process of vacuum machine

Die Preparation of the process of vacuum machine

• Die Coating: Coating the molds with a release agent to ensure that the castings drain smoothly.
• Sealing: The fuction of sealing is to create a closed system that can maintain a vacuum.

Setup of the Vacuum System

• Vacuum Channels: Fit the die with vacuum channels that connect the cavity to the vacuum pump.
• Vacuum Pump Connection: Connect vacuum pump to the channels to evacuate air from the die cavity.

Vacuum Application

• Air Evacuation: Before the molten metal is injected, the vacuum pump removes air, gases, and any moisture from the die cavity. This creates a low-pressure environment.
• Monitoring: Sensors monitor the pressure in the die cavity to ensure the vacuum reaches the desired level.

Metal Injection of of the process of vacuum machine

• Molten Metal Injection: Once the vacuum is achieved, the molten metal is injected into the die cavity under high pressure.
• Bubble Prevention: The vacuum eliminates or significantly reduces air pockets and gas entrapment, ensuring the metal fills the cavity completely and uniformly.

Solidification of the process of vacuum machine

• Cooling: The molten metal solidifies inside the vacuum-sealed die, often aided by cooling systems.
• Vacuum Maintenance: The vacuum may be maintained during solidification to ensure that no air enters the cavity and compromises the casting.

Mold Opening and Part Ejection

• Pressure Equalization: After solidification, the vacuum is released, and the die cavity is returned to atmospheric pressure.
• Part Removal: Eject the casting from the die, ensuring it is now free of porosity and other defects caused by trapped gases.

Benefits of Vacuum-Assisted Die Casting

• Reduced Porosity: Eliminates air and gas pockets, leading to stronger, denser castings.
• Improved Mechanical Properties: Enhances strength, fatigue resistance, and dimensional accuracy of cast parts.
• Better Surface Finish: Results in smoother surfaces with fewer defects.
• Increased Efficiency: Reduces scrap rates and minimizes the need for secondary operations like machining or welding.
• Larger Thin-Wall Castings: Enables the production of complex parts with thin walls due to improved metal flow.

Haichen vacuum machine for die casting machine

Haichen is a die casting machine factory located in Ningbo, China, mainly supplying cold chamber die casting machine and hot chamber die casting machine.

Besides machines, we also supply die casting auxiliary equipments, including vacuum machine, ladles and extractors and so on.

Our vacuum machine reduces porosity and enhances the mechanical properties of cast components. And it Produces smoother surfaces, reducing the need for post-processing.

If there is any requirement, please feel free to consult us.

The advantage of vacuum die casting technology is that it can significantly reduce the porosity and dissolved gases in the castings, thus improving the mechanical properties and surface quality of the castings.