ADC12, a classic Al-Si-Cu alloy, has become one of the most widely used materials in modern die casting, appearing in automotive components, electronics, and power tools. The alloy, which conforms to the JIS H 5302-2000 standard, is valued for its casting fluidity, dimensional stability, and compatibility with secondary finishing.
ADC12’s appeal begins with its chemistry. A high silicon content of 9.6% to 12.0%, combined with 1.5% to 3.5% copper, gives the alloy excellent filling performance. That characteristic makes it well suited to complex, thin-walled structures.
Its typical mechanical and physical properties are summarized below.
| Property | Typical value or range |
|---|---|
| Tensile strength | 228 MPa |
| Yield strength | 154 MPa |
| Elongation | 1.4% |
| Hardness (HB) | 74.1 |
| Density | 2.68–2.71 g/cm³ |
| Thermal conductivity | 96–120 W/(m·K) |
The combination of strength, hardness, and thermal conductivity supports both structural and heat-management applications.
High process compatibility: ADC12 offers low resistance during machining and a reduced tendency to stick to cutting tools, supporting machining efficiency gains of about 30% compared with similar alloys and helping lower overall production costs.
Dimensional stability: Its solidification shrinkage is only 0.5% to 0.7%, a critical advantage for sensor housings and complex structural parts that require high assembly precision. Precision can typically reach CT6 grade.
Surface finishing: ADC12 shows strong adhesion in painting and electroplating processes, with a blistering rate below the industry average, making it suitable for automotive exterior components.
In the automotive industry, ADC12 is used in components ranging from cylinder head covers to engine brackets. As electric vehicles gain market share, the alloy has been adopted for battery housings that must balance lightweight construction with heat dissipation.
In 5G equipment, its thermal conductivity has made ADC12 a common material for heat-sink substrates. The alloy also avoids some of the constraints associated with complex anodizing processes.
MIG welding can be used for repair, but heat input must be strictly controlled. Excessive heat can coarsen the grain structure and affect the material’s mechanical properties.
Vacuum-assisted die casting is a mainstream solution. By evacuating the mold cavity, the process significantly reduces gas entrapment and can keep porosity below 2%.
Its high silicon and copper content supports fluidity and mold filling for complex thin-wall parts, while its thermal conductivity supports use in 5G heat-sink substrates and electric-vehicle battery housings.
