aluminum extrusions vs. cast aluminum

Aluminum Extrusions vs. Cast Aluminum 

From the automotive to the aerospace industries, the use of aluminum in various applications has gained considerable momentum. 

Among these applications, aluminum extrusions and cast aluminum are common manufacturing processes, each with its own set of advantages. 

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In this blog post, we will present a comprehensive comparison of the two techniques, and while both methods have their merits, there’s no denying the superior flexibility, design freedom, and efficiency offered by aluminum extrusions.

Understanding Aluminum Extrusions and Cast Aluminum

Before we delve into the comparison, let’s understand what these processes entail.

Aluminum Extrusions

This process involves forcing preheated aluminum billet through a steel die to create a specific shape. 

Aluminum extrusions allow for complex, custom, and precision shapes with a smooth finish, making them ideal for a vast range of applications.

Common applications

  • Building and construction – Window frames, door frames, roofing systems, etc. 
  • Automotive and Aerospace – Chassis, body structures, engine parts, etc.
  • Electronics – Heat sinks, LED light fixtures, electronic enclosures, etc.
  • Public Transport – Rail infrastructure, bus and train body structures, etc.
  • Renewable Energy – Solar panel frames, wind turbine components, etc.
  • Industrial – Conveyor frames, assembly lines, machinery components, etc.

Cast Aluminum

In this method, molten aluminum is poured into a mold and allowed to cool. 

While casting allows the formation of intricate designs, it does have limitations when it comes to certain shapes and finishes.

Common applications

  • Automotive – Engine blocks, cylinder heads, pistons, etc.
  • Cookware – Pots, pans, griddles, etc.
  • Outdoor Furniture – Patio chairs, tables, etc.
  • Industrial Machinery – Gearboxes, pump housings, etc.
  • Musical Instruments – Drum cymbals, guitar amplifiers, etc.
  • Lighting Fixtures – Street lights, outdoor light housings, etc.

Aluminum Extrusions vs. Cast Aluminum – A Comparative Analysis

Now that you have a good understanding of aluminum extrusions and cast aluminum, let’s take a look at how they stack up against one another.

1. Design Flexibility

Aluminum extrusions excel when it comes to design flexibility. The extrusion process allows for a greater range of complex and precise shapes than casting. 

In extrusions, only the die needs to be designed to the desired shape, allowing intricate and detailed profiles to be achieved. 

On the contrary, casting may impose certain design restrictions, especially for larger, more complex designs.

2. Material Properties

Aluminum extrusions exhibit superior mechanical properties. The extrusion process aligns the grain structure along the length of the part, enhancing the strength and toughness of the aluminum. 

Cast aluminum, on the other hand, has an isotropic grain structure that may result in less directional strength.

3. Efficiency and Speed

When it comes to production speed and efficiency, aluminum extrusions come out on top. The extrusion process is relatively faster, permitting high-volume production in a shorter timespan. 

While casting requires a cool-down period before the next production cycle, extrusion is a continuous process that boosts production efficiency.

4. Surface Finish

Aluminum extrusions generally have a smoother and more consistent surface finish, reducing the need for additional machining or surface treatment. 

Cast parts often require secondary operations to achieve a similar finish, leading to increased production time and cost.

5. Tolerance and Precision

Extrusions provide excellent dimensional stability and close tolerances, which are particularly useful in high-precision applications. 

Casting, however, may result in shrinkage or deformation upon cooling, affecting the dimensional accuracy of the final part.

Green Manufacturing & The Sustainability of Aluminum Extrusion

In an era where sustainability is not just a catchphrase but a crucial business strategy, the aluminum extrusion process makes a compelling case for green manufacturing. A myriad of factors contributes to the eco-friendly nature of this process, from the lifecycle of the material to the energy consumption involved in its production.

Firstly, one of the most distinctive attributes of aluminum is its recyclability. Extruded aluminum is 100% recyclable, meaning that it can be melted down and reformed into new products with no loss in quality.

Inextricably tied to the recycling process is the significant energy saving that it brings about. Manufacturing new aluminum from bauxite ore is energy-intensive, requiring substantial electricity to power the extraction, refining, and smelting processes. 

On the other hand, recycling existing aluminum uses only 5% of this energy, representing a 95% energy saving. This reduced energy consumption translates into a lower carbon footprint, making aluminum extrusion an appealing option for industries aiming to reduce their environmental impact.

The sustainability of aluminum is not confined to its end-of-life recycling. The long lifespan of aluminum products, combined with their lightweight nature, also contributes to their overall eco-friendliness.

Furthermore, innovations in the aluminum extrusion process itself have led to more environmentally friendly practices. Some examples include the development of more energy-efficient extrusion presses and die technologies, improved heat recovery systems, and the use of renewable energy sources in extrusion facilities.

The Battle: Aluminum Extrusions vs Cast Aluminum 

While both aluminum extrusions and cast aluminum have their roles in manufacturing, the advantages of aluminum extrusions make it a versatile choice for many industries. 

With superior design flexibility, efficient production, and enhanced sustainability, aluminum extrusions provide an impressive blend of form and function. 

In the balance of aluminum extrusions vs. cast aluminum, extrusions indeed exhibit a shining performance.

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