Shenzhen Alu Rapid Prototype Precision Co., Ltd.

A pressure die casting machine is used to produce precise, high-quality metal parts by injecting molten metal into a mold under high pressure. This process is commonly used for alloys like aluminum, zinc, and magnesium. Below is a concise explanation of how it works, with a focus on high-pressure die casting (HPDC), as it’s the most common type, though low-pressure die casting (LPDC) shares some similarities.

How a Pressure Die Casting Machine Works

1.Mold Preparation:

A two-part metal mold (die), typically made of steel, is mounted in the die casting machine. The die consists of a fixed half (cover die) and a movable half (ejector die).

The mold is preheated and coated with a release agent to prevent sticking and ensure smooth part ejection.

2.Molten Metal Preparation:

The chosen metal (e.g., aluminum A380, zinc Zamak 3, or magnesium AZ91D) is melted in a furnace, often integrated with or adjacent to the machine, and maintained at a precise temperature (e.g., ~600–700°C for aluminum).

3.Injection System Setup:

The machine uses a shot chamber (either a hot chamber or cold chamber, depending on the alloy):Hot Chamber: Used for low-melting-point metals like zinc or magnesium. The injection system is submerged in the molten metal, allowing faster cycles.

Cold Chamber: Used for high-melting-point metals like aluminum. Molten metal is ladled into the shot chamber for each cycle to protect the machine from high temperatures.

A piston or plunger is housed in the shot chamber, ready to inject the molten metal.

4.High-Pressure Injection:

The machine applies high pressure (typically 1,000–20,000 psi or 10–200 MPa) to force the molten metal into the die cavity through a system of runners and gates.

The injection happens rapidly (within milliseconds) to fill the mold before the metal begins to solidify, ensuring intricate details and thin walls are accurately formed.

5.Solidification:

The molten metal cools and solidifies inside the die, aided by the mold’s cooling channels (circulating water or oil). Cooling time depends on part thickness and alloy but is typically a few seconds to a minute.

The high pressure is maintained during solidification to minimize shrinkage and porosity, ensuring a dense, strong part.

6.Ejection and Mold Opening:

Once the part solidifies, the die opens by separating the movable half from the fixed half.

Ejector pins push the casting out of the mold. Excess material (e.g., sprues, runners, or flash) is trimmed off.

7.Post-Processing:

The cast part may undergo cleaning, machining, or surface treatments (e.g., polishing, anodizing) to meet final specifications.

The die is cleaned, lubricated, and prepared for the next cycle.