As one of the metal extrusion processes, aluminum extrusion plays a crucial role in machining an array of machined parts. Furthermore, it is extensively employed in various industries, including construction and electricity, as it can produce intricate and accurate components.
In this article, we will delve into explaining the definition of aluminum extrusion, how it works, as well as the wide range of applications. We hope this article will give you a better understanding of this useful process.
What is Aluminum Extrusion?
Aluminum extrusion refers to a process for manufacturing aluminum profiles. In this process, manufacturers will heat aluminum ingots to a high temperature. Then they will extrude them into the desired shape through a die with a specific hole pattern. Eventually, it will achieve a variety of complex aluminum profiles. Aluminum extrusion has the advantages of low cost, high production efficiency, and high material utilization. Therefore, it is one of the essential processes of aluminum processing.
How does Aluminum Extrusion Work?
Similar to plastic extrusion, aluminum extrusion shares some commonalities in terms of working principles and practical uses. Below are some common steps:
- 1. Preheat the die to around 400-500℃.
- 2. Also heat the aluminum ingot or alloy billet to 400-500℃.
- 3. Apply release agent like lubricant to the billet and then load it into the extrusion press.
- 4. The extrusion ram pushes the billet material, applying high pressure up to 15,000 tons on the aluminum. The material will be filled with the container and extruded onto the die.
- 5. Under this high pressure, the aluminum flows through the die orifice to achieve the desired extruded profile.
- 6. Next, the puller grips the extruded part to prevent it from deformation and damage. Further, as the aluminum travels along the table, it undergoes a quenching process. It can cool the material evenly, either through a full water bath or fan cooling.
- 7. The hot saw then shears the extrusion to the table length.
- 8. Cool the aluminum materials to solidify and fix the shape, and repair some twists by stretcher.
- 9. Cut the hardened parts to the desired length, generally ranging from 8 to 21 feet. Then, move these parts into the oven for aging to reach the appropriate temperature, typically T5 or T6.
- 10. Carry out further processing like heat treatment, cutting, and surface treatment.
In general, the key aspects are the high temperature and high pressure, enabling the aluminum to flow and shape its form within the die.
Which Forms are Suitable for Extrusion?
Aluminum extrusion technology can produce a variety of complex and diverse shapes to meet the needs of different industries and applications. And aluminum extrusion can produce products in a variety of shapes, including:
- Common basic shapes, such as round, square, rectangular, oval, etc.
- Complex special shapes, including L-shaped, U-shaped, T-shaped, and H-shaped.
- Hollow shapes, from tubes to profiles.
- Shapes with notches or grooves for mounting or connecting other parts.
- Shapes with patterns or surface treatments for decoration or increased strength.
- Customized special shapes, designed and produced according to customer needs.
Different Techniques of Aluminum Extrusion
Aluminum extrusion has a variety of different techniques, mainly including the following:
- Hot Extrusion: As the above mentions, the aluminum ingot is heated to a high temperature, and then extruded through the die mold. This is the most common aluminum extrusion method.
- Cold Extrusion: it will extrude the aluminum bar at room temperature, suitable for manufacturing some simple-shaped products.
- Reverse Extrusion: The aluminum bar is pushed into the die from the exit end, opposite to the normal extrusion direction. Thus, this method can produce some special shapes.
- Bi-directional Extrusion: It can push the material simultaneously from both ends of the die, which can produce hollow structural products.
- Multi-hole Extrusion: The die features multiple holes that can extrude complex profiles with multiple holes in one operation.
- Co-extrusion: Similar to the bi-directional extrusion, it can extrude different alloy aluminum bars simultaneously, producing parts with a composite structure.
- Horizontal Extrusion: It’s able to produce longer profiles.
Considerations for Extruded Aluminum
Multiple factors need to be comprehensively considered in order to produce high-quality aluminum profiles. The main factors affecting aluminum extrusion are:
- Aluminum Composition: The chemical composition of different aluminum alloys will affect their fluidity, strength, and other properties. Thus, it will affect the extrusion process and product quality.
- Preheating Temperature: Preheating the alloy ingot at too high or too low a temperature will affect the extrusion process. Appropriate preheating temperature can improve the plasticity of the aluminum alloy.
- Extrusion Speed: Reasonable extrusion speed can ensure product quality and production efficiency.
- Die Design: The structure, material, and surface treatment of the die are responsible for the extrusion process and dimensional accuracy, and surface quality.
- Lubrication: Proper lubrication can reduce the friction force during the process and improve product quality.
- Post Processing: Processes such as aging treatment and surface treatment also impact the final performance of the product.
Pros and Cons of Aluminum Extrusion
This process has many advantages, but also some areas that need improvement. Reasonable utilization of this process can bring many benefits to various industries.
The aluminum extrusion process has the following main advantages and disadvantages:
Benefits:
- High production efficiency: It can yield mass production with precise dimensions.
- Diverse Shapes: Also, it can manufacture various complex asymmetric cross-sections to meet different application requirements.
- High Material Utilization Rate: The utilization rate is over 90%.
- Good surface quality: It can achieve various surface treatments, such as anodizing and coating, resulting in an aesthetic appearance.
- Excellent mechanical properties: The strength and hardness of the aluminum are improved after the extrusion process.
- Lightweight: Aluminum has a low density, so the products manufactured are lightweight.
Limitations:
- High Initial Investment
- Complex Mold Manufacturing
- High Energy Consumption
- Limited Material Selection
Post Treatment in Extrusion Aluminum
Post-treatment is to improve the performance and appearance of machined parts. Common post-processing methods include:
- Annealing: Softening and reducing internal stresses by heating and slow cooling to improve ductility.
- Aging: Adjusting the strength and hardness of the alloy by controlling time and temperature.
- Surface Finish: Including anodizing, coating, and electroplating, to improve appearance and corrosion resistance.
- Mechanical Processing: Such as cutting, drilling, and milling, to obtain the required size and shape.
- Cleaning and Deburring: Removing burrs and contaminants generated during the extrusion process.
Applications of Aluminum Extrusion
Aluminum extrusion products are widely used in construction, transportation, electronics, home furnishings, and other fields. Leveraging their excellent performance and characteristics, they provide innovative and developmental possibilities for various industries.
Construction Industry:
- Window and door frames
- Curtain wall systems
- Decorative moldings
- Sunshades and blinds
Transportation Industry:
- Automotive components
- Train and subway carriages
- Aerospace structures
- Ship structures
Electronics and Electrical Industry:
- Electronic device housings
- Heatsinks and heat dissipation fins
- Power cable conduits
Machinery Field:
- Machine equipment housings
- Industrial pipes and brackets
- Machine tool rails and frames
Other Applications:
- Solar photovoltaic mounting structures
- Power transmission towers
- Billboards
Aluminum Extrusion VS Die Casting
Aluminum Extrusion and Die Casting are two common aluminum processing techniques, each with its pros and cons:
| Characteristic | Aluminum Extrusion | Die Casting |
| Complexity of Shapes | High | Higher |
| Production Efficiency | High | Relatively Lower |
| Cost | Relatively Lower | Higher |
| Dimensional Accuracy | High | Relatively Lower |
| Surface Quality | High | Relatively Lower |
| Application | Large-scale Production | Small-batch/Customized Production |
Conclusion
In general, the aluminum extrusion process, with its advantages of high production efficiency, diverse shapes, high material utilization, and excellent mechanical properties, is widely employed in various industries.
Ancastings Precision has strong technical capabilities and production capacity in the field of aluminum extrusion. Additionally, we are able to provide customers with high-quality aluminum profile products and customized services. If you have any questions, feel free to contact our experts or ask for an instant quote.
FAQs
How strong is an aluminum extrusion？
Its strength can reach 200-400 MPa, which is sufficient to meet the needs of most engineering applications.
8020 aluminum alloy belongs to the 6 series aluminum one with good strength and corrosion resistance. In addition, its standard size is usually 20mm x 20mm or 40mm x 40mm, which also can be customized according to requirements.
Aluminum profiles are widely utilized in table saw fences, LED strip lights, screen enclosures, and 3D printers.
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