CNC Alloys Comparative Analysis: Advantages and Disadvantages Across Various Aluminum Alloy Grades

Aluminum, alternatively referred to as aluminium in British English, stands out as my preferred metallic element due to its exceptional strength-to-weight ratio and adaptability for diverse manufacturing applications. It constitutes a widely employed material across various industries, offering an array of aluminum alloys specifically tailored for CNC machining, CNC milling, CNC turning, welding, brazing, casting, stamping, forging, and laser cutting processes. The unparalleled versatility of aluminum renders it indispensable in sectors such as automotive, aerospace, and medical, where its unique properties play a pivotal role in enhancing performance and structural integrity.

Explore the following discourse to gain insights into a selection of prevalent aluminum alloys and their typical applications, facilitating informed material selection for your upcoming project.

Professional Tip: Each aluminum alloy elucidated in this exposition is exceptionally well-suited for CNC machining, with numerous applications extending beyond the ones explicitly enumerated for each alloy.

6061-T6 Aluminum in Technical Terms:

6061-T6 aluminum signifies a precipitation-hardened variant of the 6061 aluminum alloy. Renowned for its versatility, 6061 aluminum is a widely employed alloy amenable to heat treatment. The key alloying elements encompass silicon and magnesium, where silicon serves to lower the material’s melting temperature and enhance fluidity, while magnesium imparts heightened strength and hardness.

The ‘T6’ designation denotes the tempering process undergone by the 6061 aluminum material to bolster its hardness. The ‘T’ signifies thermal tempering, involving solution heat treatment (exceeding 900°F), followed by rapid quenching in water, succeeded by aging at a lower temperature (around 300°F) over several hours.

Advantages of 6061-T6 aluminum:

  1. High Strength and Low Density: Exhibits impressive strength with a relatively low density.
  2. Excellent Corrosion Resistance: Demonstrates notable resistance to corrosion.
  3. Machinability: Possesses favorable machinability for diverse applications.
  4. Paintability and Finish Compatibility: Facilitates ease of painting and readily accepts various finishes.
  5. Joining Capabilities: Can be effectively joined using appropriate methods.

Disadvantages of 6061-T6 aluminum:

  1. Strength Reduction at High Temperatures: Experiences a decline in strength when exposed to elevated temperatures.
  2. Welding Expertise Required: Welding demands a certain level of expertise.
  3. Susceptibility to Cracking: Prone to cracking or brittle fracturing when subjected to bending.
  4. Lower Fatigue Strength: Exhibits comparatively lower fatigue strength.

6061 vs 6063 aluminum:

  1. Consumer Products: Used in items like cabinet hardware.
  2. Automotive Components: Employed in high-strength automotive parts.
  3. Electronics Industry: Utilized for connectors and fittings.
  4. Valve Components: Applied in the manufacture of valve parts.
  5. Bicycle Frames: Commonly used in the construction of bicycle frames.
  6. Aerospace Fittings: Found in fittings for aerospace applications.
  7. Pressure Vessels: Used in the fabrication of pressure vessels.
  8. Hydraulic Systems: Employed in various hydraulic components.
  9. Marine Industry: Utilized for fittings and bodies in the marine sector.
  10. Automotive and Locomotive Frames: Integral in the construction of frames.
  11. Commercial Property Construction: Applied in the construction of commercial properties.
  12. Infrastructure: Used in infrastructure projects such as bridges and other structures.

Aluminum 7075 vs 6061

A component fabricated by CNC machining from 7075-T6 aluminum alloy. 7075-T6 aluminum represents a precipitation-hardened variant of the 7075 aluminum series, having undergone tempering to achieve the T6 condition. The principal alloying element in 7075 aluminum is zinc, imparting strength comparable to steel alloys, rendering it among the most robust commercially available aluminum alloys.

Renowned for its superior strength, 7075-T6 aluminum boasts the highest shear strength among the alloys discussed herein. This attribute has earned it designations such as “aircraft-grade” or “aerospace aluminum.” Nevertheless, the exceptional strength of 7075-T6 aluminum comes with a trade-off, as it exhibits diminished corrosion resistance in comparison to less robust aluminum alloys.

Key Advantages of 7075-T6 aluminum:

  1. Ultra-high tensile and shear strength
  2. Paintable with ease and compatible with various finishes
  3. Formability
  4. Good fatigue strength

Drawbacks of 7075-T6 aluminum:

  1. Elevated cost
  2. Reduced corrosion resistance
  3. Moderate machinability, demanding heightened precision and expertise

Common Applications for 7075-T6 aluminum:

  1. Aerospace frames and structural components
  2. Bicycle frames
  3. Tooling
  4. Gears
  5. Structural elements in marine and automotive applications
  6. Manufacturing of plastic injection molds

7050 Aluminum

7050 aluminum is characterized by its elevated strength levels and outstanding resistance to exfoliation corrosion, a form of intergranular corrosion targeting the metal at or near grain boundaries. This alloy also exhibits toughness and fatigue resistance.

Comprised primarily of aluminum, zinc, copper, and magnesium, the addition of zinc enhances strength, while magnesium contributes to increased material hardness. The presence of copper serves to bolster the alloy’s strength and facilitates precipitation hardening.

Key Advantages of 7050 Aluminum:

  1. Heat-treatable
  2. High fracture toughness
  3. Exceptional strength
  4. Outstanding resistance to stress-corrosion cracking (including exfoliation corrosion)
  5. Machinable and formable, even in thicker sections

Drawbacks of 7050 Aluminum:

  1. Suboptimal for welding due to weaker weld joints compared to 7075 aluminum
  2. Lower electrical conductivity

Common Applications of 7050 Aluminum:

  1. Aerospace structural components
  2. Rock climbing equipment
  3. Bicycle parts

2024 Aluminum Alloy Overview

The 2024 aluminum alloy stands out as a versatile and cost-effective material, albeit exhibiting lower strength compared to some counterparts within the alloy spectrum. Noteworthy for its commendable machinability and workability, this alloy lends itself well to various applications and is amenable to easy finishing processes. Its compositional foundation primarily comprises copper and magnesium, both contributing significantly to enhanced strength and hardness.

Characteristics of 2024 Aluminum Alloy:

  1. High Strength-to-Weight Ratio: This alloy excels in achieving a favorable strength-to-weight ratio.
  2. Heat Treatability: Readily responds to heat treatment processes.
  3. Machinability: Exhibits a commendable level of machinability.
  4. Durable with High Fatigue Strength: Demonstrates durability and high fatigue strength.

Despite its merits, it’s important to acknowledge certain drawbacks associated with 2024 aluminum. Notably, its heightened copper content compromises corrosion resistance, often necessitating the use of clad sheets. This strategic approach involves exposing a different aluminum alloy or an alternative metal to the external environment to mitigate corrosion concerns.

Advantages of 2024 Aluminum:

  1. Heat-treatable
  2. Formable and machinable
  3. High strength
  4. Durable with high fatigue strength

Disadvantages of 2024 Aluminum:

  1. Lower corrosion resistance
  2. Limited weldability, viable only through friction welding

Common Applications for 2024 Aluminum:

  1. Automotive wheels
  2. Aircraft structural components (including skins)
  3. Gears
  4. Engine components like pistons and cylinders
  5. Fasteners

2024 aluminum vs 6061

  1. Strength and Fatigue Resistance:
    • 2024: Exhibits higher tensile strength and fatigue resistance, making it ideal for aerospace applications.
    • 6061: While robust, 6061’s strength is slightly lower compared to 2024, but it offers excellent general-purpose strength.
  2. Corrosion Resistance:
    • 2024: Prone to corrosion, especially in high-stress environments, requiring protective coatings for long-term durability.
    • 6061: Demonstrates good corrosion resistance, particularly when compared to 2024, making it suitable for diverse applications.
  3. Weldability and Formability:
    • 2024: Limited in terms of weldability, which can be a consideration in certain manufacturing processes.
    • 6061: Excellent weldability and formability, allowing for a broader range of fabrication methods.

6061 vs 6063 aluminum

Mechanical Properties: 6061 and 6063 aluminum alloys differ significantly in their mechanical properties. 6061 aluminum boasts higher tensile strength and yield strength compared to 6063. The former exhibits superior performance in applications where structural integrity and load-bearing capabilities are paramount. On the other hand, 6063 excels in applications requiring enhanced formability and surface finish.

Chemical Composition: Understanding the chemical composition is crucial for selecting the appropriate aluminum alloy for a specific application. Both alloys are primarily composed of aluminum, with additional elements contributing to their distinctive properties. Silicon content is higher in 6061, enhancing its strength and heat resistance. Meanwhile, 6063 contains more silicon and magnesium, promoting improved formability and surface finish.

Applications: The choice between 6061 and 6063 hinges on the specific requirements of the intended application. 6061 finds widespread use in structural components, aerospace applications, and high-stress environments where its robust mechanical properties are indispensable. Conversely, 6063 is preferred for applications such as architectural extrusions, intricate shapes, and components demanding superior surface finish due to its excellent formability and aesthetic qualities.

Heat Treatment: Both alloys are amenable to various heat treatment processes that can further enhance their mechanical properties. 6061, with its higher strength, responds well to heat treatment for further strengthening, while 6063 benefits from heat treatment to improve formability and optimize its surface finish.

Mic 6 aluminum

Mic 6 aluminum is a high-precision cast aluminum plate that stands out for its exceptional flatness and dimensional stability. Engineered to meet the stringent demands of industries requiring precision and reliability, Mic 6 aluminum is renowned for its superior machinability and consistent performance.

Manufactured using an advanced casting process, Mic 6 aluminum offers a micro-structure that ensures uniformity and predictability in mechanical properties. This results in a material with minimal internal stresses, providing a stable foundation for various applications that demand precise tolerances.

The proprietary composition of Mic 6 aluminum includes elements carefully selected to enhance its thermal conductivity, corrosion resistance, and overall durability. This makes it an ideal choice for applications in industries such as aerospace, automotive, and semiconductor manufacturing, where uncompromising quality and precision are paramount.

5052 Aluminum

Alloy Overview In contrast, the 5052 aluminum alloy is distinguished by its commendable workability and electrical conductivity, making it a preferred choice across a diverse array of applications. While boasting high fatigue strength, it does exhibit comparatively lower tensile and shear strength when juxtaposed with certain aluminum alloys.

Characteristics of 5052 Aluminum Alloy:

  1. Machinable and Workable: Demonstrates excellent machinability and workability.
  2. Corrosion Resistance: Exhibits superior corrosion resistance.
  3. Weldability: Possesses weldability capabilities.
  4. High Fatigue Strength: Offers high fatigue strength.

However, it is imperative to note that the 5052 aluminum alloy has limitations, including lower tensile and shear strength, and can only be hardened through cold working.

Advantages of 5052 Aluminum:

  1. Machinable and workable
  2. Excellent corrosion resistance
  3. Weldable
  4. High fatigue strength

Disadvantages of 5052 Aluminum:

  1. Lower tensile and shear strength
  2. Hardenable only through cold working

Common Applications for 5052 Aluminum:

  1. Fuel and oil lines for aerospace and automotive applications
  2. Sheet metal
  3. Lighting
  4. Wiring
  5. Marine industry components
  6. Consumer electronics like computers and televisions

6063 Aluminum

6063 aluminum is an alloy primarily composed of aluminum, silicon, and magnesium. Its elevated silicon content makes it particularly well-suited for extrusions and vacuum brazing, exhibiting a lower melting temperature that facilitates grain boundary penetration of the braze alloy at the appropriate temperature.

Despite the inclusion of magnesium, 6063 is suitable for applications requiring moderate strength and operating under normal temperature conditions. Its formability allows for the creation of intricate shapes, and it possesses high corrosion resistance, maintaining a polished appearance over its operational lifespan.

Advantages of 6063 Aluminum:

  1. Smooth, lustrous appearance
  2. Paintable and accepts finishes easily
  3. Excellent metal joining properties (welding and brazing)
  4. Heat treatable
  5. Suitable for complex geometries
  6. High corrosion resistance

Disadvantages of 6063 Aluminum:

  1. Lower strength
  2. Not easily machined

Common uses for 6063 Aluminum:

  1. Piping
  2. Railing
  3. Heat exchangers
  4. Decorative products like furniture
  5. Electrical conduit
  6. Commercial and residential architectural components like window frames

MIC-6 Aluminum

MIC-6 aluminum is a precision cast aluminum known for its exceptional rigidity and consistent tolerance. Manufactured through a patented continuous cast process, MIC-6 ensures a stable, deformation-free cast plate, addressing issues of distortion and temperature-related deformation during machining and use. Widely utilized for precision measurement equipment due to its high precision machining capabilities.

Advantages of MIC-6 Aluminum:

  1. Excellent dimensional stability
  2. Can be machined to tight tolerances
  3. Resistant to distortion and deformation
  4. Outstanding machinability with uniform chip production
  5. Cast material free of voids and impurities

Disadvantages of MIC-6 Aluminum:

  1. Care required when welding (preferably MIG welding)
  2. Moderate corrosion resistance
  3. Not formable

Common uses for MIC-6 Aluminum:

  1. Fixturing equipment like jigs
  2. Precision measuring equipment like gauges
  3. Robotics components
  4. Electronics components
  5. Medical industry parts
  6. Tooling for the automotive and aerospace industries
  7. Hydraulic equipment

Main Takeaways

Understanding the diverse properties of aluminum alloys aids in selecting the ideal material for CNC machining projects. Consider factors such as strength, precision, and corrosion resistance when choosing between alloys like 6063, 7075, and MIC-6 to suit the specific requirements of your application.

Streamlined Procurement – Initiate Your Subsequent Project with BOYI

After finalizing your selection of the optimal aluminum alloy for your upcoming project, the subsequent task involves identifying a supplier, and BOYI serves as your bespoke manufacturing operating system, facilitating accelerated, simplified, and more efficient part procurement. In essence, BOYI empowers engineers, such as yourself, to focus on engineering.

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