Aluminum Die Casting vs. Zinc Die Casting

Which metal contender reigns supreme in the world of die casting?

Thanks to its popularity in the manufacturing industry, aluminum is the undisputed champion choice in die casting—but that doesn’t mean it doesn’t have some strong competition. 

When it comes to producing complex parts on a large scale, custom die casting tends to be the manufacturing technique of choice. But die-cast products are only as good as the metals being used in their production.

Die casting typically employs non-ferrous alloy metals, and the four most commonly used are aluminum, zinc, magnesium alloys, and copper. The choice of die-casting materials comes down to several factors, including density, melting point, strength, resistance to corrosion, and cost. 

If you’re wondering which type of die casting is right for your next project, aluminum or zinc, you’re in the right place. Read on to learn which metal comes out on top for die casting.

Aluminum die casting is the heavy favorite for a good reason

Aluminum remains the heavy favorite contender for an unexpected reason: its light weight! The metal is prized for its ability to create extremely lightweight components without sacrificing strength. An aluminum die casting company can create a great range of surface finishes, as well. You can go with a smooth finish to give your products a nice aesthetic sheen or, if desired, a more textured surface.

Aluminum die casting has a higher startup cost than some other processes because of a lengthy tooling process. However, the process can produce less expensive per-unit costs over the long term, especially for mass production, because less machining is required per unit.

This is because lubrication of the die keeps things cool, reducing concern over high temperatures, which can lead to metal burning. That lubrication makes it easier to remove the freshly cast metal products, too. 

The surprising stats of zinc die casting

Even as aluminum weighs in as the most popular metal in die casting, zinc holds its own as another very popular choice. Zinc alloys punch above their class because they boast a high density, similar to steel, which makes them strong and heavy alternatives to most other die casting materials. This high density gives zinc high impact resistance, and makes zinc the material of choice for castings for structural applications. 

Zinc has high impact strength, which makes it suitable for producing parts for industrial manufacturing and mechanical design. 

Zinc also has a low melting point, which means it requires less energy for production. This also extends the life of the mold, an important cost-saving factor in die casting.

Ultimately, your choice of tooling material depends on the product you are manufacturing plus its application. 

Industry Showdown: Aluminum vs. Zinc

Aluminum die casting can produce extremely complicated parts that are resistant to corrosion. Other manufacturing processes can’t achieve the complexity and tight tolerances, which makes aluminum die casting ideal for the production of complicated parts like agricultural assemblies and electrical vehicle battery housings.

Aluminum die casting is also popular in the construction industry for roofs, solar panels, window frames, and other components for bridges and cell towers; in the furniture industry for door handles, hinges, knobs, and other metal hardware parts; and in the electronics industry for mobile phones, networking hardware, and heat sinks. 

On the other hand, zinc is typically used for casting products for the automotive and medical supply industries. With zinc, fabricators can produce components capable of custom aesthetic quality as well as strict and narrow tolerances.

Zinc boasts impressive corrosion-resistance and heightened thermal conductivity, making it a durable, hard, and stable material. And because it’s non-ferrous, only containing trace amounts of iron, zinc (like aluminum) doesn’t rust. 

Whenever items are being customized for aesthetic purposes, zinc castings tend to be the best choice. That’s because zinc offers a smooth surface that can be plated or painted, depending on the need. 

What is the process for aluminum die casting?

Aluminum die casting is the go-to process for many industrial projects that require metal parts. The aluminum die casting process involves pushing molten metal into a metal mold called a “die” that has been machined with two halves into the shape desired.

The two halves are clamped together by a machine before the molten metal is injected into the open space. Once the casting has solidified, the die is opened and the piece is removed. 

Depending on the project, aluminum die casting can be done via a “hot” or “cold” process. In hot die casting, a hydraulic-powered piston is critical for forcing molten metal into dies for casting. Cold casting can work with more materials, but it involves an extra step and a separate chamber. Once the metal has been melted down, it is then transferred via an injection cylinder into another machine for casting.

What is the process for zinc die casting?

The process for zinc die casting is very similar to the process for aluminum die casting. However, while aluminum can be cast through hot chamber casting or cold chamber casting, metals like zinc and tin that have lower melting points are better suited to hot chamber casting. 

Hot die casting machines feature built-in furnaces in which the metal is heated up in real-time during the process. Hot die casting is a quick die casting method, with a typical start-to-finish casting time of just 15 minutes.

Whether you go with aluminum or zinc, we’re in your corner

Pictured above: An aluminum die cast housing manufactured by TFG USA.

Whichever you choose, aluminum or zinc, your project will come out on top with The Federal Group. We have decades of experience producing high-quality custom metal products, and we’d love to assist with your next die-casting project. 

We can help with custom die-casting to achieve precise measurements, complex shapes, multiple components, high dimensional accuracy, and corrosion resistance. We bring a collaborative approach and production part approval process to create more efficient, high strength, cast parts and components. 

Contact us to get started on a free quote for your die casting project today.