1. Introduction

Die casting is a metal casting process characterized by forcing molten metal under high pressure into a mold cavity. The mold is typically made of high-strength steel and is capable of producing components with excellent dimensional accuracy and surface quality. Due to the high cost of casting equipment and molds, die casting is most suitable for mass production of medium- and small-sized components. Compared with other casting methods, die-cast parts have smoother surfaces, more consistent dimensions, and higher production efficiency.

Common die-casting metals include zinc, copper, aluminum, magnesium, lead, tin, and their alloys—most of which are non-ferrous. Depending on the metal and casting requirements, either cold-chamber or hot-chamber die casting machines are used.

With technological development, several advanced processes have been derived from conventional die casting, such as vacuum die casting (to reduce porosity), direct injection die casting (for improved yield), squeeze casting, and semi-solid die casting.

2. Characteristics of Aluminum Alloy Die Casting

Wide application range

High dimensional accuracy and low surface roughness

High production efficiency

High metal utilization rate

High strength and surface hardness

Compared with zinc alloys, aluminum alloys offer superior mechanical and thermal properties. They exhibit good die-casting characteristics, excellent electrical and thermal conductivity, and favorable machinability. However, aluminum-silicon alloys can adhere to molds easily, cause corrosion to metal crucibles, and have larger solidification shrinkage, which may result in shrinkage defects. Due to these factors, molds for aluminum alloy die casting are typically more expensive and require higher maintenance than those for zinc alloys.

3. Thermal Conductivity and Heat Dissipation Performance

(1) Material Properties

Aluminum alloys generally have a thermal conductivity of 150–200 W/m·K, depending on the composition (e.g., ADC12, A380, or 6063). This is significantly higher than that of plastics (<1 W/m·K) and most steels (≈50 W/m·K).

Therefore, aluminum alloy lamp housings exhibit excellent heat dissipation performance, making them ideal for LED and automotive lighting applications where high thermal efficiency is required.

 In addition, the low density of aluminum (2.7 g/cm³) allows for lightweight designs without compromising structural strength.

(2) Structural and Process Advantages

Die casting enables the formation of complex geometries such as fins, air channels, and honeycomb structures, which improve convective and radiative heat dissipation. Unlike extruded aluminum profiles, die-cast housings can be produced as single, integrated parts, minimizing assembly interfaces and reducing thermal resistance. 

Die-cast structures are dense and continuous, providing efficient heat transfer paths. Advanced processes such as vacuum or porosity-free die casting further enhance thermal performance.

However, improper die-casting parameters may lead to gas porosity or shrinkage cavities, which reduce local thermal conductivity. Moreover, aluminum-silicon alloys have slightly lower thermal conductivity compared to pure aluminum or 6063 alloys.

4. Comparison with Other Heat Dissipation Materials

5. Conclusion

Aluminum alloy die-cast lamp housings provide a balanced combination of thermal performance, strength, and cost-efficiency.

High thermal conductivity

Excellent design flexibility for optimized heat dissipation

Smooth surface and consistent quality for mass production

Slight reduction in thermal performance if porosity or high silicon content exists

In summary, aluminum alloy die casting represents one of the most effective and widely adopted solutions for thermal management in modern LED lighting systems.