If you’ve decided to make your products from aluminum and are exploring manufacturing options, you may be trying to determine which processing or forming method to use. Two major contenders are die casting and extrusion, but what is the difference between cast aluminum and extruded aluminum? Before we compare them, we first need to define what each process entails.
Die cast aluminum products are made by melting aluminum ingots, injecting the molten metal into a die mold using a power cylinder or piston, and then letting the aluminum solidify into the die mold’s shape as it cools. While the process is somewhat more complex in practice — including steps like adding alloying elements and deburring — the general principle is relatively straightforward.Here is an example of a die cast automotive part.
Die castings can be done in a wide range of sizes and can accommodate complex geometries — like automotive engine blocks, for example. After creating a tool steel die mold, you can cast the product numerous times before the mold deteriorates and you need to replace it.
The number of times you can reuse a mold depends on the shape of the part, the allowable tolerances for the end product, and processing conditions. For more information, please view our What is Aluminum Die Casting? article.
Extruded aluminum products are made by forcing a heated aluminum billet through a die to produce the desired cross-section. The extrusion can then be cut to an appropriate length and subjected to further processing — like machining bolt holes or fitting together different parts for the final product.
We have provided a complete description of the aluminum extrusion process in our article What is Aluminum Extrusion? The Process in 10 Steps.Here is an example of an extruded aluminum profile.
Aluminum extrusions are well-suited to high production outputs, where they rapidly produce reliable, high-strength aluminum products as a result of the work-hardening that occurs during forming.
Both die casting and aluminum extrusion have excellent advantages and a few disadvantages that make them better suited for certain applications. To help you decide which process is best for you, take a look at the side-by-side comparison below:
Both die casting and extrusion can be excellent methods for making your aluminum products.
Die castings are generally more costly upfront, but depending on the parts being manufactured, you could save money on post-casting machining and assembly costs. Extrusions can be limiting in terms of shape-possibilities and may require additional post-forming machining and assembly. However, they are generally stronger and less expensive to produce.
The choice you make ultimately depends on the specifics of your project, as you can expect different mechanical properties and manufacturing costs with each processing method.
Learn more about:
➔ The Aluminum Extrusion Process
➔ The Aluminum Die Casting Process