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Aluminum High Pressure Die Casting Alloys composition intricacies. A headache for designers?

By 26 June, 2024Technical Blog

In the realm of manufacturing, aluminum die casting alloys stand out as a versatile and highly sought-after material. alumini preferred choice for a wide array of industrial applications.  This becomes many times in a big headache for designers because the range alloys to be used is related to the manufactoring process.

Let’s delve into some interesting technical topics.

Aluminum alloys are organized and identifed based on its composition. Combination of elements are indicated by specific number series from 1 to 8.

High preassure die casters use to work with group 4 alloys based on Silicon which is the first alloying element and plays a crucial role in improving fluidity and reducing shrinkage.

Silicon content has a direct influence on the raw material properties and is to be considered relevant at process.

Comercial alloys for HPDC usually contain from 5 to 15% of Silicon. it makes the alloy castable , that means capable  to readily fill and solidifiy castings with no hot tearing or hot craking issues.


Higher silicon % at alloy leads to lower thermal expansion coefficient and higher wear resistance.

Silicon combined with other alloying elements like Magnesium can even improve strenght and make the alloys heat treatables to improve even more after casting and this has been attractive for the industries looking for Iron based alternative materials.

Other interesting alloying elements are:

  • Copper enhances strength and hardness and increases the matrix hardness. This is specially good for machining because generate small cutting chips and fine machined surfaces but has negative impact on corrosion resistance of the products.
  • Manganese: In a controled % cause beneficial changes to the morphology of iron phases and contributes to minimize the undesired “soldering” effect of the alloy to the die surface.
  • Zinc contributes to increased fluidity and lower melting temperatures so is good for the process itself.

Modyifying elements as Titanium (Ti) , Boron (B) or Stroncium (Sr) are being added to new alloys in terms of achieving even better performance in terms of fatigue resistance for instance.

The current goal of the casting companies nowadays is having as much knowledge as posible about all these topics to help the customers to find the right alloy for their products.

All the clear benefits of the Aluminum alloys in terms of performance and suntainability will lead for sure to a huge industrial possibilities in the near future.

Aluminum alloys as alternative to steel alloys vs corrosive agents.

Aluminum resists the type of progressive corrosion that causes steel to deteriorate progressive degradation. The exposed surface of the aluminum is combined with the oxygen from the air to form a film of aluminum oxide (inert), only about ten millionths of an inch thick, which blocks rust. Unlike iron oxide, the aluminum oxide film does not comes off, thereby not exposing any part of its surface to the subsequent oxidation. If the aluminum protective layer is scratched or broken it is instantly sealed and re-formed. This thin layer of rust clings firmly to the metal, is colorless and transparent-invisible to the eye. view. Discoloration and peeling of iron and rust of steel do not occur in aluminum. Properly alloyed and treated, aluminum can resist corrosion by water, salt, and other media; plus a wide range of other chemical and physical agents.

Aluminum alloys as very good option for emobility products:

Aluminum has excellent electrical and thermal conductivity, but some specific alloys have been developed with high degrees of electrical resistivity. These alloys are useful at high-performance and big torque electric motors. Aluminum is often selected for its electrical conductivity  which is almost double that of copper.

Conductivity and mechanical strength are sometimes necessary in high voltage lines.

The thermal conductivity of aluminum alloys is approximately 50 to 60% that of copper, it is advantageous in heat exchangers ,evaporators, and other electric heating devices.


There is no alloy better than another, you simply have to find the one that best adapts to the requirements of each product and for this purpose qualified casting suppliers can be a very interesting source of knowledge to rely on.