Aluminum Alloy Die-Cast Automotive Parts

Aluminum alloy die-casting is a widely used lightweight technology in the manufacturing of automotive parts. Especially in the era of new energy vehicles, integrated die-casting enables the formation of complex structural parts, which can significantly reduce vehicle weight, improve efficiency, and reduce welding processes. The die-casting process mainly utilizes high pressure to inject molten aluminum alloy into a mold, achieving the production of high-precision, complex-shaped castings.
 

Main Manufacturing Steps

The aluminum alloy die-casting process can be divided into preparation, forming, and post-processing stages, as follows (based on standard hot chamber or cold chamber die-casting machine processes):

1. Alloy Melting: Select an aluminum alloy suitable for automotive parts (such as ADC12 or A380) and heat it in a furnace to approximately 650-700°C to melt it. It is necessary to control impurities and gas content to ensure the purity of the molten metal.
2. Mold Preparation: The mold is usually made of H13 steel, preheated to 150-250°C, and coated with a release agent. Large-scale integrated die-casting molds for automobiles require high-precision machining to accommodate complex geometric shapes.
3. Molten Metal Pouring and Injection: Pour the molten metal into the injection chamber (cold chamber machine) or inject it directly from the crucible (hot chamber machine), and then inject it into the mold cavity at high speed (30-60m/s) and high pressure (50-150MPa). Vacuum assistance can reduce porosity defects.
4. Cooling and Solidification: The molten metal in the mold cools and solidifies within a few seconds to tens of seconds, forming the casting. The cooling time depends on the wall thickness and mold design, and is usually controlled at 80-90 seconds/piece to achieve efficient production.
5. Mold Opening and Part Removal: The mold is opened, and the casting is removed using ejector pins or robots. Care must be taken to avoid damaging the surface.
6. Trimming and Cleaning: Remove runners, flash, and overflow material, and clean the surface using a vibrating screen or sandblasting.
7. Heat Treatment: Perform T6 heat treatment (solution treatment + aging) to improve strength and corrosion resistance, suitable for automotive chassis or body parts.
8. Machining and Surface Treatment: CNC machining is used for precise hole positions, and spraying or anodizing is used for rust prevention. Final inspection of dimensions, strength, and defects.