In recent decades, aluminum extrusion has significantly increased product design and manufacture. According to a recent Technavio analysis, the global aluminum extrusion market will develop faster between 2019 and 2023, with a Compound Annual Growth Rate (CAGR) of about 4%.
You may have heard of this manufacturing method and need clarification on what it is and how it functions. In this article, we'll talk about aluminum extrusion, including what it is, its advantages, and how it works.
Aluminum extrusion is a manufacturing method where alloy material is forced into a die with a specific cross-sectional shape. A powerful ram pushes the metal through the die and out of the aperture. When this occurs, it emerges in the precise shape of the die and is carried away along a runout table.
Fundamentally speaking, the procedure is a straightforward technique. When you press a tube of toothpaste with your hands, the same force is used. When you squeeze the toothpaste tube, it emerges as the aperture. The toothpaste tube's aperture serves a similar function to an extrusion die.
There are two main types of aluminum extrusion processes. They include:
Direct Extrusion is the most used method for extruding aluminum. The aluminum extruder places the heated aluminum billet in a heated walled container. The metal is then pushed through the die by a moving ram. This process generates a significant amount of pressure.
Additionally, material blocks are frequently put between the billet and the ram by machinists. By following this process, the hot billet and ram are kept apart. Since the aluminum billet and the ram travel forward, this procedure is also known as a forward extrusion process.
The indirect process is also known as backward Extrusion, and it is distinct from the direct method. Here, the billet and container move concurrently while the die stays motionless. Manufacturers carry out this technique using a "stem." The stem that holds the ram in place must be longer than the container's length. As a result, the stationary die is pushed through with the aluminum billet.
This method produces less friction than the direct method, which results in better heat regulation. Indirect extrusions make higher-quality products that are more consistent. This might be a result of the applied force being largely constant. Additionally, the stability of the temperature guarantees improved grain structure and mechanical qualities.
Let's have a look at the ten steps of the aluminum extrusion process:
First, prepare the extrusion die and transfer it to the extrusion press.
First, an H13 steel die with a circular shape is manufactured. Or, if one is already on hand, it gets taken out of a warehouse like this one.
To prolong its life and ensure consistent metal flow, the die must be warmed to between 450 and 500 degrees celsius before Extrusion. The die can be loaded into the extrusion press after it has been heated up.
Next, a long log of the alloy material is carved into a solid, cylindrical block of an aluminum alloy known as a billet. Then prepare to a temperature of 400 to 500 degrees celsius in an oven. Despite not being molten, it is now sufficiently malleable for the extrusion process.
The billet is mechanically moved to the extrusion press once it has been warmed. However, before loading it onto the press, lubricate it or treat it with a release agent. Engineers can also apply the release agent to the billet and ram to prevent them from sticking together.
Now that the malleable billet has been placed into the extrusion press, the hydraulic ram is exerting up to 15,000 tons of pressure. The billet material is forced into the extrusion press's container as the ram exerts pressure. The substance enlarges to fill the container's walls.
The extrusion die is now being forced against the alloy material as it fills the container. The aluminum substance is constantly under pressure, and it can only escape through the die's opening(s). It pops out of the die's aperture as a completely formed profile.
A puller grabs the Extrusion as it emerges from the press and moves it down the runout table at speed corresponding to its escape from the press. The profile is "quenched," or uniformly cooled, as it goes along the runout table by a water bath or fans above the table.
A hot saw is used to shear an extrusion once it has reached the entire length of the table to remove it from the extrusion process. Temperature is crucial at each stage of the procedure. The Extrusion hasn't completely cooled down even though it was quenched after leaving the press.
Table-length extrusions are mechanically moved from the runout table to a cooling table after shearing. They will remain there until the profiles reach room temperature. After that, they'll undergo stretching.
The profiles have been twisted naturally, and this needs to be fixed. To fix this, they're transferred to a stretcher. Once it is completely straight and brought into the specification, each profile is mechanically grasped at both ends and pulled.
The table-length extrusions are moved to the saw table once they are straight and completely work-hardened. Here, they are sawed to predetermined lengths, typically between 8 and 21 feet long. The extrusions' characteristics now match those of the T4 temper. They can be placed in an aging oven after being sawed and aged to the T5 or T6 temper.
Four main types of shapes are made by Extrusion:
● Solid: There are no holes or openings in these shapes (i.e., beam, angle, or rod).
● Empty: They have one or more gaps or holes in them (i.e., rectangular or square tubes).
● Partially hollow: They have voids that are only partially filled, like a "C" channel with a small gap.
● Custom Shapes Made from Aluminum Extrusions: These shapes often have more than one Extrusion. They could also be different-colored shapes that fit together. These shapes are often made to meet the needs of the designers.
Aluminum extrusion is an excellent way to make product parts, but the process results depend on several things. To ensure your project goes well, keep these things in mind.
How hard and much it would cost to extrude a part would depend on its shape. Extrusion can make many different shapes, but there are some limits. For instance, it would be much easier and faster to extrude simple solid shapes than semi-hollow ones. They would also be cheaper because, in general, the more complicated the shape, the more complex and more expensive it is to make.
In general, the speed of Extrusion is directly related to the pressure and temperature of the metal inside the container. So, you must set up the speed, pressure, and temperature correctly to keep the process steady and make an extruded segment that stays the same.
The best temperature for a billet is one that allows for good surface and tolerance conditions. It also makes sure that the cycle time is as short as possible. Extruding billets should always be done at the lowest temperature the process will allow.
If the temperature is too high, the metal will flow more easily. This would make the metal not want to go into small spaces. So, the shape's measurements might need to meet the desired tolerances. In the same way, metal can tear at sharp corners and thin edges if the temperature is too high.
Aluminum extrusion is the only way to make parts with cross-sectional profiles that are exactly what you want. It's an exciting process, and you can get products in different shapes that you can heat treat, make, and finish to your needs. Ares Prototyping has the best aluminum extrusion services to get the desired result. Contact us immediately, and we'll help you make your project happen. You can also upload your design file to our digital quotation platform to get instant quotes and a straightforward ordering process.
