Aluminum is one of the most machined materials today. In fact, aluminum CNC machining processes are second after steel in terms of frequency of execution. This is mainly due to the excellent machinability.
In its purest form, the chemical element aluminum is soft, ductile, nonmagnetic, and silvery-white in appearance. However, the element is not only used in its pure form. Aluminum is typically alloyed with various elements such as manganese, copper, and magnesium to form hundreds of aluminum alloys with various significantly enhanced properties.
Is Aluminum good for machining?
Aluminum as a material offers some interesting thermal and mechanical properties. Also, the aluminum metal is relatively easy to shape, especially in drilling processes like CNC aluminum machining. In fact, we value an aluminum alloy very much compared to other light metals such as magnesium and titanium alloys.
The use of CNC aluminum has increased immensely, the production of CNC automotive parts and other lightweight CNC parts has been intense.
Why is aluminum easier to machine than steel?
Aluminum is easier to cut than steel, allowing for faster machining and shorter lead times. Although aluminum is considered too soft for mass production, this is simply not true.
Some aluminum molds are capable of producing parts after 2 million cycles! Aluminum cools much faster and more evenly than steel. This shortens the cycle time and saves money.
Because aluminum is so light, it can be machined on smaller machines and faster too. Aluminum dissipates heat very evenly, allowing for great dimensional stability through less warping. There is far less scrap because there are far fewer cracks and warps.
Aluminum is often viewed as a weak, soft material that is not good for mass production. However, aluminum can actually be used for high volumes. It can also be machined faster and dissipates heat much faster and more evenly than steel. This often shortens throughput times and saves money.
Which Aluminum Grade is Use for Parts Fabrication?
The final choice of the type of aluminum grade you want to use depends on your machining projects, which allow you to classify each grade according to its characteristics, from the most important to the least important. This allows you to choose the aluminum with specific properties and shapes according to your needs.
The following are some types with essential facts about the Aluminum grade;
- Aluminum 6061: This grade has excellent mechanical properties and excellent weldability. Its topical properties make it one of the most extruded strains. This is because of its good toughness, medium and high strength, excellent corrosion resistance under harsh conditions, cold anodizing and bend workability. Aluminum 6061 is commonly used for 5-axis CNC machining.
- Aluminum 7075: Also popular, although not like 6061. This grade is known for its exceptional fatigue strength. This type of aluminum is not suitable for welding; it is expensive. Therefore, it is better suited for heavy-duty parts such as fuselages, bicycle parts, climbing equipment and airplane wings. This alloy also has better corrosion resistance.
- Aluminum 2024: The alloy is mainly used in the military and aerospace sectors. This is due to its mechanical properties such as high wear resistance and high strength. The 2024 aluminum has terrible corrosion resistance and is not weldable.
5 Ways to Fabricate Aluminum Parts
Aluminum is a widely used material for manufacturing mechanical parts. Because it is easy to work with, lightweight, and strong metal. In addition, there are various methods of applying a surface finish to protect aluminum from corrosion and give it a beautiful appearance.
Because we use aluminum in a wide range of applications, there are 5 different ways to produce aluminum parts: Aluminum CNC Machining, Aluminum Extrusion, Sheet Metal, Aluminum Casting, and Aluminum Forging. Below we go through these 5 ways to produce aluminum components and semi-finished products.
1. Aluminum CNC Machining from A Full Block or Bar.
CNC machining is the simplest type of aluminum machining. We mount an aluminum block on a milling machine. Or we clamp a bar in a lathe to machine it with a cutting tool.
The principle of both ways is to cut metal chips with a cutting tool to get the desired shape of the product. On a milling machine, the cutting tool rotates. With a lathe, on the other hand, the product rotates.
Machining aluminum parts enables high cutting speeds. Also, with good liquid cooling, we get a nice finish on the part. However, depending on the direction of feed, there is often a difference in surface roughness compared to the direction of rotation of the tool. Did you know that alcohol is a very good coolant for cutting aluminum? It makes the machined surfaces of aluminum CNC machining parts shiny.
The advantage is that almost any shape can be processed. However, unless we’re using a 5-axis CNC machine, we’ll have to rotate and clamp the part to the machine on each side. And there is a lot of scraps, which affects unit costs.
2. Aluminum Extrusion
Extrusion is a process for the production of semi-finished products. To illustrate, we heat an aluminum rod to deformation temperature. Next, a piece about 500 millimeters long is cut off. Then the operator places this piece in the infeed of the extrusion machine.
In the end, we force the aluminum through a hardened steel extrusion die. The result is a long piece of aluminum with the desired section of the product. These pieces are usually 12 meters long. After extrusion, the strips are straightened. Now we cut the long pieces to the desired length of the end product. In most cases, the product still needs to be processed.
The benefit of extruded aluminum products is that there is a large reduction in waste material to get the final part. However, the product range is fixed and the number of built-in functions is limited.
3. Aluminum Sheet Metal
Sheet metal fabrication is another type of 5 ways to make aluminum parts. We assume a thin sheet of aluminum. Next, we cut the aluminum sheet into the right shape. That’s why we use laser cutting machines and punching machines.
There are flat sheet metal parts and curved products. The aluminum sheets are bent with a bending machine, but also with punching machines and presses.
4. Aluminum molding and casting.
There are different ways of molding aluminum parts.
Injection molded aluminum parts.
We also do aluminum injection molding. Liquid aluminum is injected into an injection mold under high pressure. As a result, we get parts with almost all desired properties after they come out of the mold. This technique is only suitable for the production of large quantities since the injection mold is relatively expensive.
Sand casting of aluminum parts.
The mold cost is much cheaper in sand casting, but you have to accept the rougher shape and surface of the products. Sand castings have larger tolerances and the material is more brittle due to low-pressure casting.
In most cases, the cast aluminum parts still have certain features to the machine. For example, we use our CNC machines to machine cavities with tight tolerances. Also, we drill and drill threaded holes after molding. Cast aluminum parts are not suitable for anodizing due to the structure of the material. Therefore, they are usually powder-coated.
5. Aluminum Forging
And finally, among the 5 ways to make aluminum parts is forging aluminum parts. This is another way to reduce waste. We literally press a block of aluminum between a positive and negative side of a hardened steel mold.
Therefore, our factory uses a large press with a pressure of 5000 tons. As a result, we get a perfectly formed part. Just like the injection molding process, we post-process burrs, holes, and tapped holes for a more accurate product.
Aluminum products processed with a press are suitable for anodizing because the structure is similar to that of extruded aluminum. This aluminum part manufacturing process begins to be profitable for production runs in excess of 3000 pieces.
If you are looking for CNC machining, vacuum casting, pressure dies casting, 3D printing, rapid tooling and injection molding, sheet metal prototyping, plastic, and aluminum extrusion services, you should definitely go with a manufacturer like 3ERP.
They are providing high-quality manufacturing solutions that can have your design finished in a matter of hours. This gives you the opportunity to rigorously test your product, and make all the needed changes to perfect your design before it goes into full-scale production.