3 Types of Aluminum Casting Methods

The question “Which aluminum casting method should I use?” requires asking and answering further questions.

You must consider the application at hand, the requirements of the project overall, and your needs as a customer. This is as true for aluminum casting methods as it is for any other process.

Are you looking for the fastest production speed or is strength of the utmost importance? Are you planning to produce a few pieces or hundreds of thousands? Each of the aluminum casting methods have different benefits, and the answers to questions like these will guide you to the right one.

The benefits and applications of using aluminum casting techniques for a project are vast. However, you must consider several further choices when deciding how to Cast Aluminum parts for your application.

We’ll quickly summarize the differences between the available methods, and provide an easy guide to determine the right choice.

Aluminum Casting Methods: The Three Processes

Three primary metal casting methods can be used to cast aluminum: die casting, permanent mold casting, and sand casting. The methodology behind each of these metal casting techniques is as follows:

What is Aluminum Sand Casting?

In this method, using a pattern, we create a mold from a sand mixture. Any necessary cores are then placed inside the cavity, allowing for the creation of parts with greater complexity.

We then pour a molten aluminum alloy into the mold through “runners,” which were inserted into the mold during its creation. Once the aluminum cools and solidifies, the sand mold is broken away from the part.

Finally, we do any finishing work that is necessary to have the part meet the customer’s specifications.

What is Permanent Mold Casting?

As the name implies, in this aluminum casting method, the mold is not broken away (as it is in sand casting).

Just like in sand casting, the mold is formed from a pattern. Molten aluminum is then poured into the mold. Once cooled, the mold is removed and any necessary finishing work is done to the part.

The difference, though, is in the makeup of the mold itself. Whereas sand casting, of course, uses a sand mixture to create the mold, in permanent mold casting metal is used.  The mold is also created in two halves. This allows the mold to be separated instead of broken apart once the part is cooled.

What is Die Casting?

Die casting is very similar to permanent mold casting, except that the molten aluminum is injected into the cavity under pressure, rather than poured and filled via gravity.

Aside from this functional difference, the two processes are similar, but we’ll discuss the differences in the output below.

Which Aluminum Casting Technique Should You Choose?

But how does each fare in the common factors that contribute to which method is right for you? Along with a brief overview of each factor, we’ll note which of the three processes meets that need best:

• Speed: Sand Casting’s automated processes, like at LeClaire Manufacturing, provide a high output of parts in a short period time compared to permanent mold processes. Die casting provides the greatest speed in manufacturing, thanks to the pressurized injection process.
• Strength: Permanent mold casting provides the greatest material strength in the finished product. Although similar to die casting, the pieces produced via permanent mold casting are stronger due to the nature of the process.
• High quantities: Sand Casting offers the most advantageous balance between higher quantities and tooling costs, although that lessens as the quantities rise. Permanent mold is a closer second. For quantities well in excess of 100,000, however, die casting may be the better choice.
• Prototypes and short runs: Sand casting is the method of choice when creating only a few pieces, thanks to its low tooling cost.
• Surface finish: Permanent mold casting and die casting offer the smoothest surface finish out of the mold.

If you have additional questions about the right process for you, LeClaire Manufacturing is ready to help. To learn more about our one-stop sand casting, permanent mold casting, or die casting services, contact us today to receive a quote.