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The Complete Guide to Aluminum Extrusion
Among the numerous materials available in the market, aluminum excels due to its unique combination of properties, including strength, flexibility, and lightweight. Aluminum extrusion is a key process in maximizing the potential of aluminum.
In this guide, we will dig into the complexities of aluminum extrusion, highlighting its applications and its significance among the various aluminum profiles available.
Whether you are a professional in the industry, a DIY enthusiast, or someone analyzing the possibilities of aluminum profiles, we encourage you to keep reading and find all the details.
What Is the Aluminum Extrusion Process?
The aluminum extrusion process starts with a billet, which is a solid cylindrical block of aluminum alloy heated to about 900°F (482°C). Once heated, the billet is placed into an extrusion press, where a ram uses pressure to push the aluminum through a die. As the aluminum floats through the die, it takes on the cross-sectional shape of the die’s profile.
After extrusion, the aluminum undergoes a series of cooling processes, which may include air or water cooling. This solidifies the material and helps it maintain the desired shape. Following the cooling process, the extruded aluminum is cut to length, heat-treated, and finished according to specific application requirements.
Why Use Aluminum Extrusion?
It’s a valid question, and the answer is straightforward. Aluminum extrusion offers four key advantages, making it one of the easiest materials to operate with.
- Strong, Clean, and Modern Aesthetic: The industrial style is currently popular, and aluminum profiles can be customized to provide the necessary strength for various designs while remaining lightweight. Additionally, they are corrosion-resistant, making them suitable for diverse environments and climates. These profiles can even be rated for clean room applications.
- Aluminum Extrusion is Versatile and Modifiable: Numerous profiles, shapes, and sizes are compatible with the t-slot design framework, complemented by a comprehensive library of handles, plates, casters, gussets, brackets, and more. These components can be assembled in any configuration you choose, and they are suitable for both large architectural projects and small custom designs. Additionally, the modular framing connections allow for easy disassembly and customization for subsequent projects, all while minimizing material waste. To correct a workstation that is too tall, loosen some screws, adjust the height, and re-tighten them. For further customization, you can also drill additional holes.
- Easy to Assembleand Disassemble: Assembling the framework takes just a few minutes and is straightforward—insert the connectors into the T-slot and tighten them using basic hand tools. The connections are strong yet non-permanent, eliminating the need for welding. You can join the materials wherever and whenever you like, keeping the large construction mess for someone else to handle.
- A Cost-Effective Solution. Custom profiles can help save money by minimizing the demands for additional welding or joining processes. The lightweight nature of aluminum also makes handling and shipping more cost-effective. Whether you’re dealing with small or large orders, extrusion is an economical method for producing parts. Additionally, buying surplus lengths of aluminum extrusions enables you to cut them to your specific requirements, making it a budget-friendly option for many projects.
The Extrusion Process
Aluminum extrusion is a commercial manufacturing process used to produce aluminum profiles for various construction applications. The aluminum profile undergoes several procedures to meet specific requirements and standards throughout this process. Additionally, the process includes treatments such as anodizing, powder coating, and painting to ensure that the profile can resist harsh environmental conditions and prevent corrosion and rust.
We have outlined the major steps in the aluminum extrusion process to help you understand the processes involved in aluminum profile manufacturing.
- Billet Preparation:The process starts with preparing aluminum billets, which are cylindrical logs made of aluminum alloy. These billets are generally heated to a specific temperature to enhance their malleability for extrusion.
- Container Heating:The extrusion press container, also referred to as the “billet holder,” is preheated. This preheating reduces the force required for extrusion, ensuring a smoother process.
- Die Heating:The extrusion die is a specially designed tool that shapes aluminum and is heated during the process. Typically, the die is made from tool steel, which must endure high temperatures and pressures during extrusion.
- Billet Loading: The heated aluminum billet is placed into the extrusion press container, which is designed to exert tremendous pressure on the billet, forcing it through the extrusion die.
- Extrusion Process:The press exerts pressure on the billet, pushing it through the shaped opening of the extrusion die. As the aluminum moves through the die, it adopts the desired profile, forming a continued length of the extruded shape.
- Cooling:The extruded aluminum profile is quickly cooled using air or water quenching methods. This step is essential for defining the shape and guaranteeing the structural integrity of the extruded profile.
- Stretching and Straightening:Some profiles may experience a stretching process to align the aluminum molecules and relieve internal stresses. Straightening is also conducted to ensure the extruded profiles meet the specified tolerances.
- Cutting to Length: The extruded aluminum is continuously cut into individual profiles of specified lengths. This precision cutting guarantees uniformity and allows for easier further processing.
- (Optional) Surface Treatment and Finishing:Extruded profiles may undergo surface treatments like anodizing, painting, or powder coating based on design specifications and application needs to improve their appearance, durability, and corrosion resistance.
- Quality Control:This step includes thorough quality control measures, such as surface finish, inspections for dimensional accuracy, and overall compliance with specifications, to ensure that the extruded profiles meet required standards.
- Packaging and Delivery:Finally, the completed aluminum profiles are securely packaged to ensure protection during transportation. They are then delivered to customers for further fabrication or assembly for their intended uses.
The careful management of the extrusion process makes aluminum extrusion a preferred option in industries that require high-quality and precisely formed components.
Materials Used in Aluminum Extrusion
Table 1：The table below lists the common grades of aluminum used for extrusion:
| Common Grades | Other Grades |
| Aluminium 6063 | Aluminium 1060 |
| Aluminium 1050 | Aluminium 3003 |
| Aluminium 6082 | Aluminium 5083 |
| Aluminium 6042 | |
| Aluminium 6060 | |
| Aluminium 6061 | |
| Aluminium 6262 | |
| Aluminium 7180 |
The Common Types of Aluminum Extrusion
Aluminum extrusion is valued for its ability to allow manufacturers to create durable, strong, and customizable products tailored to their specific needs. The main types of aluminum extrusion include direct extrusion, indirect extrusion, hot extrusion, warm extrusion, as well as cold extrusion.
Direct Aluminum Extrusion
Direct extrusion is the most typical method. A billet, heated to 800 degrees Celsius, is pushed through a die that shapes the aluminum extrusion.
Aluminum extrusion brackets are commonly used in various applications. The 7000 series of alloys, particularly the 10 series aluminum extrusion, are ideal for this process.
Indirect Extrusion
The indirect extrusion method operates differently. In this case, the die moves towards the stationary billet, which reduces friction and leads to improved surface finishes.
Indirect extrusion is ideal for creating precise components, such as aluminum extrusion rails. Standard aluminum extrusion profiles are generally produced using this method.
Hot, Warm, and Cold Extrusion
Hot, warm, and cold extrusion are defined by the temperature of the billet in relation to room temperature and the material’s recrystallization temperature.
Hot extrusion happens when the billet is heated significantly above its recrystallization temperature and is often associated with direct extrusion processes. Heating the material softens it and prevents work hardening, allowing it to flow more easily through the die, which in turn reduces tool wear.
Warm extrusion takes place when the material is heated above room temperature but remains well below the recrystallization point.
In cold extrusion, the material is not heated and remains at room temperature throughout the process.
Warm and cold extrusion processes can improve the hardness and strength of extruded products due to minimal heating of the raw materials. These methods are particularly effective with highly ductile materials like aluminum. Both warm and cold extrusion are common techniques used in indirect metal extrusion. While avoiding excessive heating is beneficial, it can make the tooling more challenging to work with and shorten the lifespan of the die. For this reason, many manufacturers prefer hot extrusion methods.
What Shapes Can Be Extruded?
There are four primary types of extruded shapes:
- Solid Shapes:These shapes don’t have any enclosed openings or voids, such as beams, angles, or rods.
- Semi-solid Shapes: Shapes such as angles, channels, and other partially open forms.
- Hollow Shapes: They have one or more openings or voids, specifically in the form of rectangular or square tubes.
- Custom Aluminum Extrusion Shapes: These shapes often feature multiple extrusions and may interlock with different color profiles, all crafted according to the designers’ specifications.
Factors that Affect Aluminum Extrusion
Alloy Selection: Different aluminum alloys possess varying properties and are suitable for distinct applications. Selecting the appropriate alloy is crucial for the final extrusion’s strength, durability, and other characteristics.
Extrusion Temperature: The aluminum temperature during the extrusion process plays an important role in determining the quality of the final product. It is essential to control the temperature carefully to ensure that the aluminum is sufficiently soft for extrusion while avoiding excessive heat that could make it brittle or cause degradation.
Speed of Extrusion: The speed of aluminum extrusion impacts the quality of the final product. Extruding too quickly can cause defects and reduce dimensional accuracy while extruding too slowly can prolong production times and increase costs.
Die Design: The die applied in the extrusion process is crucial for shaping the final product. A well-designed die can reduce defects and enhance the overall quality of the extrusion.
Cooling Rate: The cooling rate of extruded aluminum impacts its strength and properties. Adequate cooling is essential for the aluminum to retain its desired characteristics.
Lubrication: Effective lubrication of both the aluminum and die is crucial to reduce friction and prevent the aluminum from adhering to the die.
Tongue Ratio: The tongue ratio also plays a crucial role in determining the extrusion performance of a part. To calculate the tongue ratio, first, square the size of the smallest opening in the void. Next, compute the total area of the shape and divide the squared opening by this area. A higher tongue ratio indicates that the part will be more challenging to extrude.
Common Surface Finishes Used for Aluminum Extrusions
Various surface finishes are commonly applied to enhance aluminum extrusions’ aesthetic and functional qualities. The following are four types of post-processing typically used for aluminum extrusions:
Powder Coating
Metal parts are dusted to achieve a lustrous and textured finish. You can select any color combination to enhance the decorative appeal of the part.
Oxidation
Oxidation is a chemical process that enhances the corrosion resistance and textured appearance of aluminum extrusions by adding an oxide layer to the surface.
Sandblasting
Sandblasting not only hides cutter marks on the surface of metal parts but also adds texture. When sandblasting is done on these parts prior to oxidation, the resulting oxidized aluminum extrusions will achieve a more matte finish.
Silk Screen
If you want to add a distinctive icon to each aluminum extrusion’s surface, silk screen printing is a suitable post-processing method that can assist you in achieving this.
The Applications Of Aluminum Extrusion
Architecture and Construction
Aluminum profiles are widely used in the architectural and construction industries. They provide sleek window frames, curtain walls, and strong structural components, enhancing modern and sustainable building designs with their precision and strength.
Medical Equipment
Aluminum extrusions are utilized in the medical industry for various applications, including manufacturing hospital beds and some other medical equipment.
Industrial Machinery
Aluminum extrusion is preferred in various industrial machinery components because it produces intricate and precisely shaped profiles. Examples of where these profiles excel include conveyor systems, frames, working tables, protective cells, and trolleys.
Electronics and Technology
The electronics and technology sectors utilize aluminum profiles for their lightweight and corrosion-resistant properties in manufacturing casings, heat sinks, and structural components across various devices.
Automotive Innovation
In the automotive field, aluminum extrusions’ lightweight and durable nature plays a crucial role. From intricate interior designs to chassis components, the automotive sector benefits from the versatility and formability of aluminum profiles.
Consumer Products
Aluminum extrusions are utilized in diverse consumer products, such as appliances, furniture, and sporting goods.
Transportation
Aluminum extrusions are utilized in transportation, including manufacturing trains, buses, and various other vehicles.
Aerospace
Aluminum extrusions are utilized in the aerospace industry for structural components and various applications, where a strong yet lightweight material is essential.
Renewable Energy
Because the world turns to renewable energy solutions, aluminum extrusion is essential in producing solar panel frames, wind turbine components, and other elements vital to the sustainable energy landscape.
Conclusion
Aluminum extrusion is a vital and cost-effective manufacturing process known for its design flexibility across various industries. This method can make numerous complex and detailed shapes, making it an excellent choice for products with intricate designs. Furthermore, extruded aluminum is a lightweight, strong, and durable material that resists corrosion and can withstand harsh environments.
