If you have ever asked yourself what extruded aluminum actually is, well, you should know that it is nothing less than the result of an extrusion process. This one allows you to obtain basically any kind of extruded profiles in the shapes and dimensions you need - even the tiniest ones.
As a matter of fact, aluminum is employed in several sectors - for instance, we see it in door or drawer handles, window frames, handrails etc. A recent forecast by Technavio, a global market research company, states that the aluminum market has the potential to grow by 6.76 million tons in the years between 2020 and 2024.
But where do aluminum extrusions come from? And how does aluminum extrusion work? Discover it in this page:
Aluminum extrusion is a process used to transform aluminum alloy into objects by forcing the material through a die under high pressure with a specific cross-sectional profile, to create complex shapes. The process involves heating a cylindrical billet of aluminum to a temperature where it becomes malleable, and then pushing it through a die to produce the desired shape.
Aluminum’s malleability allows it to be easily machined and cast; at the same time, being one-third the density of steel, the resulting objects are characterized by remarkable strength and stability.
During the extrusion process, a ram pushes the aluminum through the die and it emerges from the die opening in the same shape as the die. It is then pulled out along a runout table.
The resulting shapes can be either simple or complex depending on the die shape, and can also have very tiny dimensional tolerances, like those Profall is able to achieve. In fact, a variety of aluminum profiles and objects can come out of the extrusion process. We can divide them into three main categories:
To get a better idea on what you can obtain from aluminum extrusion, take a look at our Aluminum Extrusion Catalog.
The following ten steps briefly explain how is extruded aluminum made from the moment we design the die until extrusions are moved to the saw table.
The first step involves designing the die for extrusion and making it from H13 steel. Before extrusion, it is preheated to between 450°C and 500°C: it is a way to maximize its life and ensure metal flow.
It is now the moment to load it into the extrusion press.
A solid, cylindrical billet is cut from a log of aluminum alloy, and preheated in an oven between 400°C-500°C. The preheating step makes it malleable enough to undergo the extrusion process, but not molten.
A lubricant or release agent is applied on the surface of the aluminum billet and to the extrusion ram to prevent them from sticking together. The billet is now mechanically pushed to the extrusion press.
The hydraulic press applies up to 15,000 tons of pressure on the aluminum billet, which is pushed into the container of the extrusion press, expanding in such a way to fill the walls of the container.
A continual pressure is applied to the billet, which now goes out through the openings in the die: it emerges in the shape of a fully-formed aluminum profile. To avoid the formation of oxides, nitrogen in liquid or gaseous form is introduced through the sections of the die. This creates an inert atmosphere and increases the life of the die.
To be made, the extruded aluminum profile needs to pass onto a run-out table and be uniformly cooled by a water bath or by fans above the table.
Once the profile reaches its full table length, it is sheared by a hot saw to separate it from the extrusion process. At this point, the extruded profile has not yet fully cooled.
It is now time to transfer table-length extrusions to a cooling table, where fans cool the newly created aluminum extrusion. It will stay here until it reaches room temperature.
During the cooling process, it may occur that aluminum extrusions undergo some natural twisting which, of course, need to be corrected. So, they are moved to a stretcher for straightening and work hardening.
The hardened extrusions are brought to the saw table and cut to the required length.
You may think that now extruded aluminum profiles are fully made. Not yet. As a matter of fact, the very last step of the extrusion process consists of treating the aluminum with heat inside an age oven that hardens the material while speeding up the aging process.
In the oven, aluminum profiles are usually aged until T5 or T6 temper. This is necessary to improve its mechanical properties such as tensile strength and yield stress.
Additional complexities may be applied during the extrusion process to customize the extruded parts. For example, pins or piercing mandrels are placed inside the die to create hollow sections.
Depending on the final use of the extrusion you require, you may also need some surface finishing to adjust the color, texture and brightness of the aluminum’s finish or to make it resistant to rust and corrosion.
We can divide surface finishing treatments into three main categories:
Anodization is a galvanic, or electrochemical, process that aims to create a layer of oxide on the surface of the extrusion. The final purpose is to improve aluminum’s resistance to corrosion caused by atmospheric agents or rust by improving surface emissivity. In addition, the layer of oxide makes the surface porous so that it can accept various colored dyes - from neutral tones to bronze shades ranging from light champagne to dark.
If you have specific aesthetic requirements, powder coating is the solution as it applies a layer of colored material upon the extrusion surface. It is commonly an epoxy or electrostatic polyester powder coating that adheres to the surface, which needs to undergo a secondary treatment to render the coating layer uniform.
Profall makes coated extrusions in all the RAL colors - including special aesthetic effects such as wood-like textures.
These are just three of the many available options that allow us to create a piece of extruded aluminum with the exact dimensions and specifications you need.
For instance, we can drill screw holes into a structural piece or cross machine fins to obtain a specific pin design.
Other mechanical and finishing processes include:
Customization is really Profall flagship. Getting a bit into details, it means that:
Most part of the requests we receive is focused on the production of extruded aluminum pieces with extremely tiny dimensional tolerances, which are quite hard to find on the common aluminum market. For instance, tubes have standard dimensional tolerances of +/- 0.15 mm per side, but we can produce them also with smaller dimensions and all the mechanical characteristics and complexities you need.
The choice of which alloy to use is directly depending on the final use of the extruded profiles and their mechanical features. At Profall we basically extrude aluminum from three different alloys:
You can learn more about this topic here: Aluminum Alloy Extrusion: How to Choose the Right Alloy for Your Product
The most common alloys requested by our clients are 1050, 1070, 3103 and 6060, with which we manufacture:
Aluminum extrusions have several applications across various sectors, such as:
At Profall, we specialize in providing top-tier extruded aluminum services, tailored to meet the diverse needs of our clients. Our expertise in extrusion technology allows us to produce aluminum profiles with exceptional precision and quality, even with the most challenging shapes and sizes.
Whether it's for construction, automotive, electronics, or any other industry requiring the strength, lightness, and corrosion resistance of aluminum, Profall stands out as your go-to partner. We offer a wide range of customizable solutions, from standard shapes to complex custom designs, ensuring that each product not only meets but exceeds our clients' expectations.
With a commitment to innovation and customer satisfaction, Profall's extruded aluminum services are designed to deliver efficiency, durability, and aesthetic appeal. Choose Profall for all your extruded aluminum needs and experience a partnership that drives your projects to success.
