Choosing the right type of aluminum alloy for your CNC machining requires an understanding of the various characteristics and benefits each alloy will have. Aluminum alloys are in great demand in industries related to aerospace, automotive, and manufacturing because of their strength, flexibility, and good machinability. In this article, we are going to look at a few aluminum alloys, such as 6061-T6, 7075-T6, 7050, 2024, 5052, 6063, and MIC-6, and weigh the pros and cons of each to help you make an informed choice for your project.
6061-T6 Aluminum
6061-T6 is one of the most used types of aluminum alloys in CNC machining. It offers a perfect balance between strength, flexibility, and anti-corrosion properties, which justifies its wide application in aerospace, automotive, and building construction. It has excellent machinability with great value for money.
6061-T6 has good weldability and forms well, hence it could be used for components such as frames, brackets, and structural parts. Its moderate strength makes it versatile, though not as strong as some other alloys like 7075-T6 or 2024 aluminum, hence limiting its use in high-stress applications.
Pros:
Good balance of strength, flexibility, and machinability
Excellent corrosion resistance
Affordable and readily available
Suitable for a variety of applications, including structural components and aerospace parts
Cons:
Not as strong as 7075-T6 or 2024 aluminum
7075-T6 Aluminum
7075-T6 is considered one of the strongest types of aluminum alloy; hence, it is a favorite in many highly stressed and high-performance applications. Being widely used in both aerospace and military industries, the alloy is applied in those components that call for excellent strength, including aircraft frames, weapons, and high-performance machinery.
7075-T6 features excellent fatigue resistance and strength-to-weight ratio, making it one of the best choices for critical parts. The added strength also makes it a bit more difficult to machine than softer alloys, such as 6061. It is also more expensive and thus used only when necessary for less demanding applications.
Pros:
One of the strongest aluminum alloys
Excellent for high-stress, high-performance applications
Ideal for aerospace components
Good fatigue resistance
Cons:
More expensive than 6061 and 5052
Slightly more difficult to machine compared to 6061 due to its higher strength
Lower corrosion resistance than 6061-T6
6061 Aluminum Vs 7075 Aluminum
The major difference between 6061 and 7075 is in strength versus cost. 7075 is much stronger, more resilient, and used in heavy-duty applications such as aircraft structures. On the other hand, 6061 has superior machinability and corrosion resistance; for less demanding uses, 6061 is an economical alternative.
7050 Aluminum
7050 is heat-treatable aluminum alloy exhibiting very high strength coupled with resistance to exfoliation corrosion and stress-corrosion cracking. Major applications are currently in aerospace industries for structural parts that require the combination of high strength and resistance to stress corrosion.
This alloy has better resistance to exfoliation and stress corrosion cracking compared to 7075. Although it offers high strength and good machinability, it is more expensive and less commonly available, which may limit its use in some projects.
Pros:
Exceptional resistance to stress corrosion cracking
Excellent machinability
High strength and fatigue resistance
Cons:
More expensive than 6061
Less widely available compared to other alloys like 6061 or 7075
2024 Aluminum
2024 aluminum alloy is a kind of high-strength aluminum alloy used in the aerospace industry with high intensity, low weight, excellent fatigue resistance, and high strength-to-weight ratio, which makes it the most proper material for aircraft parts, including wings and fuselage parts. On the other hand, its corrosion resistance is low compared with other alloys; hence, its use requires a protective coating.
2024 Aluminum is a high-strength alloy that is ideal for structural parts in the aerospace industry but is not really suitable for use in applications that are exposed to the elements unless some sort of additional protection is applied.
Pros:
High strength, especially in thinner sections
Excellent fatigue resistance
Ideal for aerospace components
Cons:
Poor corrosion resistance (often requires coatings)
Difficult to machine due to its hardness
2024 Vs. 6061 Aluminum
2024 Aluminum retains greater strength but gives up corrosion resistance compared to 6061 and is not as suitable for aircraft that are exposed to the elements. For structural parts requiring great strength, however, 2024 is the better choice.
5052 Aluminum
5052 aluminum alloy has excellent resistance to corrosion, in particular, in seawater and industrial atmospheres. It is widely used for building tankers, pressure vessels, and boat hulls. Excellent weldability, good formability, and its higher strength make this alloy suitable for general use.
However, 5052 does not provide the same level of strength as 6061 or 7075 alloys, which restricts its use in structural applications requiring high strength.
Pros:
Excellent corrosion resistance, particularly in marine environments
Good weldability and formability
Ideal for tanks, marine, and pressure vessel applications
Cons:
Lower strength compared to 6061 and 7075
Less commonly used in high-performance aerospace applications
6063 Aluminum
6063 aluminum is the same as 6061, but it is commonly used in architectural and ornamental applications since it has a good surface finish with a medium strength. It is often used in window frames, doors, and other extruded parts.
6063 aluminum has excellent corrosion resistance and good machinability, making it suitable for applications where aesthetics are important. However, it is generally not as strong as 6061, 7075, or 2024 and is thus not seen in high-stress, load-bearing applications.
Pros:
Excellent surface finish
Good corrosion resistance
Often used for architectural and decorative purposes
Cons:
Not as strong as 6061 or 7075
Limited use in high-stress applications
Difference Between 6061 And 6063
6063 is softer than 6061 and provides much better surface finish characteristics. As such, this makes it perfect for aesthetic applications such as window frames and other architectural uses. For structural purposes, though, it does not have the same strength that 6061 provides.
MIC-6 Aluminum
MIC-6 is a hot-cast aluminum tool plate with excellent dimensional stability and very good machinability. Its high degree of flatness and accuracy makes it ideal for precision applications like tooling, fixtures, and molds.
While not as strong as the 7075 or 2024 alloys, MIC-6 aluminum is valued for its very good machinability and fine surface finish. Stability and precision make it ideal for high-precision, low-stress applications.
Pros:
Excellent machinability and surface finish
High dimensional stability and flatness
Ideal for tooling, fixtures, and molds
Cons:
Not as strong as other alloys like 7075 or 2024
More expensive than some other aluminum alloys
How To Choose The Right Aluminum Alloys For Your Project?
The choice of the right aluminum alloy for your CNC machining project will depend on several factors such as the strength required, machinability, corrosion resistance, and cost. In projects that call for high strength, alloys like 7075 and 2024 come in handy, particularly in aerospace and military applications. Where the requirement is for general machining and the costs and ease of machining are important, it is better to use 6061 or 5052 alloys.
Strength Requirements: The best usages for high-strength applications would be 7075 or 2024 aluminum. If the balance has to be between strength and flexibility, then 6061-T6 is the ideal one.
Corrosion Resistance: If your components will face harsh environments, alloys like 6061 and 5052 will offer great corrosion resistance.
Machinability: Alloys such as 6061-T6 are easily machined, while harder alloys, such as 7075, may require special tooling.
Cost: Alloys like 6061-T6 and 5052 are considerably cheaper, while 7075 and 7050 could be quite expensive.
Application: The choice alloy would be different depending on your application, whether it be a lightweight, high-strength material for aerospace or a corrosion-resistant alloy for marine applications.
Conclusion
The selection of the right type of aluminum alloy for a CNC machining project is pretty important because it ensures better performance and cost-effectiveness. Whether you need the strength of 7075 aluminum in aircraft parts, the corrosion resistance of 5052 in marine applications, or the versatility of 6061-T6 in general applications, understanding the pros and cons of each alloy will help guide your decision.
Ultimately, choosing the right type of aluminum alloy for your project comes down to its requirements concerning strength, machinability, and corrosion resistance, while considering one’s budget.
Final Thoughts
As a 15-year veteran in the CNC machining service, I’ve seen firsthand the impact of material choice on project success. When it comes to aluminum alloys, each has its strengths and weaknesses.
For instance, 6061 is a workhorse, offering good machinability and corrosion resistance, making it suitable for general-purpose parts. However, for applications demanding high strength-to-weight ratios, 7075 excels, though it can be more challenging to machine.
At Ultirapid, we pride ourselves on material expertise. We recently helped a client design a lightweight drone component using 7075, achieving the required strength while minimizing weight. Our in-depth knowledge of aluminum alloys ensures we recommend the optimal material for your specific CNC machining needs.
Faqs
Does Aluminum Alloys Rust?
No, aluminum alloys do not rust because rust specifically refers to the oxidation of iron or steel. Aluminum, being a non-ferrous metal, cannot undergo this process. Instead, it forms a thin, protective layer of aluminum oxide when exposed to air, which prevents further corrosion. However, some aluminum alloys, like 2024 and 7075, are less resistant to corrosion due to their copper or zinc content. Protective measures such as anodizing or coatings can enhance durability in harsh environments.