Die Casting

This is a very practical question. The short answer is: Yes, it's strong – but it depends on how you use it.

Where Does Die-Cast Aluminum's Strength Come From?

Die-cast aluminum is widely used because it performs well in several key areas:

High strength-to-weight ratio. Commonly used alloys like ADC12 or A380 have a tensile strength of 250–320 MPa, which is roughly 60% to 80% that of ordinary steel. However, aluminum has only about one-third the density of steel. This means that for the same weight, an aluminum part can be made thicker and more rigid. That's why industries like automotive and aerospace use large amounts of aluminum alloys – they are lightweight but strong enough.

Good impact resistance. Die-cast aluminum is not a brittle material. It has decent toughness and can absorb and dissipate impact energy. The fact that components like automotive wheels and engine mounts – parts that bear dynamic loads – are made from it says a lot.

Hardness can be improved through heat treatment. After T6 solution and aging treatment, the hardness of die-cast aluminum can be further increased, enhancing its wear resistance and resistance to deformation.

What Are Its Limitations?

Die-cast aluminum's strength does have its boundaries:

Limited fatigue strength. If a part needs to withstand millions of repeated stress cycles – such as high-speed rotating components – die-cast aluminum doesn't perform as well as steel. Under long-term alternating loads, it is more prone to fatigue cracks.

Susceptible to high temperatures. Above 150–200°C, the strength and hardness of aluminum drop significantly. It is not suitable for parts that operate under continuous high heat, such as exhaust manifolds or turbo housings.

Casting defects can compromise strength. If the process is not well controlled during die-casting, internal porosity or shrinkage cavities may form. These micro-defects can significantly weaken localized strength. That's why critical structural parts typically require X-ray inspection to ensure they are free of internal defects.