Why Aluminum Alloys for Gravity Die Casting?

Manufacturers always consider cast aluminum a perfect choice for new product designs. This article will help you understand why manufacturers prefer aluminum alloys for gravity die casting to produce various cast metal components.

Why Aluminum Alloys for Gravity Die Casting

Low Melting Temperature

Stainless steel requires temperatures above 2,500 degrees F to melt, and stainless steel casting requires temperatures above 3,000 degrees F. However, aluminum castings require a lower temperature, 1,221 degrees F, to melt.

Aluminum melting and casting temperatures also depend on some other metals mixed into the alloy. However, aluminum alloys require less than half the temperature for casting compared to ferrous alloys containing iron or steel.

Aluminum alloys have a low melting temperature, making them less energy-intensive and less expensive for gravity die casting than ferrous alloys. They also require less time to stabilize. This improves plant efficiency and reduces cost.

Excellent Malleability

If a substance deforms without breaking or cracking, this ability is called malleability. Metals, especially gold, exhibit high levels of malleability compared to other material groups. However, cast aluminum also exhibits malleability, which makes it more sophisticated with other positive attributes.

Aluminum foil is one of the best examples of aluminum’s malleability. A roller press is used to press high purity aluminum, which results in aluminum foil. This process reduces the thickness of the metal to the required size. The aluminum foil we use daily in our kitchen can be as thin as 0.00017 inches, 400 times thinner than an average human hair.

Lightweight marine hardware parts are preferably made of aluminum because of their low malleability. Gravity die casting is generally the most appropriate process for producing marine equipment parts. In this process, molten aluminum alloys are poured into the mold for solidification. Many industries such as bicycles and food machinery use aluminum casting to provide strong and lightweight products.

Light Weight

Cast aluminum has a lower weight than cast iron and cast stainless steel. This shows that the finished cast aluminum product is much lighter than a cast iron or stainless steel product with the same shape.

Again, the alloying elements make a difference in the actual measurement; the best thing is that cast aluminum is about 2.5 times less dense than cast steel. However, cast aluminum is not as firm or hard as cast steel, but we have some design flexibility because of its lightweight. For example, a 5-pound gravity cast aluminum part can hold 2.5 times more material by volume than a 5-pound cast steel part.

Excellent Corrosion Resistance

Aluminum castings have a high resistance when exposed to weathering and other reactive elements. Various metals have the property of forming an oxide layer on their outer surface when they react with water or oxygen in the atmosphere.

Oxidative corrosion such as rust can be commonly observed in metals that form less stable oxide layers. Cast aluminum and other such metals react with oxygen in the same way. Still, they do not maintain a durable microscopic thickness, so their oxide layers continue to grow until they are visible to the naked eye.

In contrast, cast aluminum forms a stable oxide layer, which becomes a barrier against further oxygen reaction. Interestingly, if the surface of a cast aluminum part is damaged, the layer “heals” immediately.


Cast Aluminum can definitely be called an exceptional metal. However, some factors determine whether or not it is a suitable material for your product. If you would like a detailed solution for your next aluminum alloy gravity die casting project, let CFS Foundry help you!

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