6061 vs 6063: Unveiling the Differences in Aluminum Extrusion Applications

From construction to the automotive and aerospace industries, aluminum extrusions are of pivotal importance. Of the numerous available aluminum alloys, 6061 and 6063 are the most common. Each is unique in its characteristics and serves different purposes. Knowing the differences is important in choosing the best-fitting material for your project. This article provides a detailed analysis of the differences between 6061 and 6063 with regard to their composition, mechanical features, and the cases in which each would be most suitably employed. Engineers, manufacturers, and the merely curious about material choice will appreciate the essential information presented here and will be able to choose wisely.

What is 6061 Aluminum?

6061 aluminum is a widely used aluminum alloy that has very good mechanical properties as well as corrosion resistance. It consists of aluminum, magnesium, and silicon which make it relatively strong, tough, and light. This alloy is adaptable and versatile due to its heat treatability, enabling its use in structural parts and components, automotive parts, aerospace frames, construction materials, among others. It is also popular throughout multiple industries due to its good machinability and weldability.

Understanding 6061 Aluminum Properties

The combination of strength and lightweight make 6061 aluminum a direct fit for applications that need long-lasting efficiency alongside minimal weight. The corrosion resistance provided by the alloy, particularly against moisture and weather, guarantees durability over time. Its supple heat treatment leads to extraordinary mechanistic capabilities such as increased hardness and tensile strength. 6061 aluminum possesses high weldability and good machinability, allowing for precision and flexibility in fabrication and manufacturing processes. These qualities all together make it widely accepted in the aerospace, automotive, and construction industries.

Applications of 6061 Aluminum in Extrusions

6061 aluminum extrusions are employed in a number of industries due to their strong properties in combination with corrosion resistance, as well as their versatility. The following is a comprehensive list of the industries where 6061 aluminum extrusions are critically useful:

Aerospace Components

• Used in structural aircraft parts like the wings, fuselages, and landing gears.
• It provides lightweight, high-strength performance, which is essential for aerospace engineering.
• This is common in satellite structures in the upper atmosphere due to the material’s durability in extreme environments.

Automotive and Transportation

• Required in the manufacture of vehicle chassis, frames, and body panels.
• Added associated with a reduction in the weight of the vehicle; improves fuel efficiency and performance.
• Commonly used in the construction of railcars so as to improve corrosion resistance and longevity.

Architectural and Construction Applications

• It serves as a framework for bridges, roofing systems, and curtain walls.
• Often used in windows and doors because of its high machinability and anodized finish.
• Ideal for lightweight structural supports that cater to new-age architectural needs.

Marine Industry

• Required for the construction of ships and for making marine hardware, as well as constructing docks.
• Offers the best corrosion resistance to saltwater when compared to other materials.
• Helps in the fabrication of structures that are lightweight yet strong for boats.

Electrical and Energy

• Applied in heat sinks for electrical components for its good thermal conductivity.
• Used in the construction of solar panel frames and for systems of renewable energy.
• Used in structures where a low power-to-weight ratio is required.

Industrial Machinery

• Commonly used in jigs and fixtures, precision machined parts are tools of industrial machinery.
• Industrial equipment ensures durability and reliability in high-stress areas.
• Industrials provide cost-effective performance for heavy-duty components.

Consumer Goods

• Recreational gear, camera equipment, and bicycle frame production are common for goods consumers.
• Exceptional Lightweight properties combined with remarkable strength make it durable.
• Gives anodized aesthetic finishes for consumer products.

In terms of technology and efficiency in manufacturing, the 6061 aluminum extrusions are of diverse use. It is their flexibility that makes them essential in so many different fields.

6061 Aluminum Alloy Composition

6061 aluminum alloy consists of aluminum at its core, with magnesium and silicon being essential parts of the alloy. The typical composition is as follows:

• Aluminum (Al): 95.85% to 98.56%
• Magnesium (Mg): 0.8% to 1.2%
• Silicon (Si): 0.4% to 0.8%
• Iron (Fe): 0.7% maximum
• Copper (Cu): 0.15% to 0.40%
• Chromium (Cr): 0.04% to 0.35%
• Zinc (Zn): 0.25% maximum
• Titanium (Ti): 0.15% maximum

This combination delivers optimum strength and corrosion resistance, which makes it useful for a number of industries. Magnesium and silicon are major constituents that help copper and chromium precipitation hardened alloy components to increase their strength. While iron and other trace constituents are present in the alloy, their concentration is strictly controlled to ensure that consistent properties of the alloy are produced. The chemical composition confirms suitability for the aerospace, automotive, and structural industries where reliability and performance while using the components are of significant importance.

Exploring 6063 Aluminum Alloy

Key Features of 6063 Aluminum

• Superb Corrosion Resistance: 6063 aluminum has extraordinary resistance to corrosion in different surroundings. It works especially well against atmospheric and marine environments which minimizes maintenance efforts and costs over time.
• Good Weldability: The alloy can be welded with ease by the use of ordinary welding methods like TIG or MIG welding. Its compositional make up allows clean and robust welds to be achieved as well as minimal material degradation.
• High Extrudability: 6063 is well known for its very good extrudability which is strongly important for manufacturing complex profiles and shapes, that are used for architectural and structural purposes.
• Moderate Strength: The alloy exhibits reasonable mechanical performance while maintaining formability with an ultimate tensile strength of 35,000 psi (240 MPa) and yield strength of 31,000 psi (214 MPa) in the T6 temper.
• Excellent Surface Finish: 6063 is anodized easily giving appealing and long lasting surface finishes that are great for decoration and protection, which make the alloy superb for anodizing processes.
• Good Thermal Conductivity: Having approximately 201 W/m·K for thermal conductivity, 6063 aluminum is highly effective in dissipating heat and is therefore desirable in heat exchangers, radiators, and cooling components.
• Lightweight: 6063 is an aluminum alloy and, so has a density of around 2.7 g/cm³ which leads to weight savings in applications where mass is a primary concern.
• Recyclability: 6063 can be recycled completely, supporting green manufacturing and life cycle management efforts in several industries.

These properties combined highlight the versatility and usefulness of 6063 aluminum across various industrial and commercial sectors.

Advantages of Using 6063 in Extrusions

• Outstanding Resistance to Corrosion: 6063 aluminum has remarkable corrosion resistance, especially in areas that are prone to the presence of water and air. A 6063’s corrosion resistance ability is due to a natural oxide coat that forms on a material’s surface preventing further oxidation. For example, it is commonly used in the construction of outdoor structures and marine facilities which are frequently moistened.
• Good Thermal Conductance: For heat dissipation parts like heat sinks and cooling systems, 6063 is ideal because of its thermal conductivity of about 201-218 W/m·K. This advantage is valued among electronic and automotive companies as well.
• Superior Surface Finish: This alloy is known to anodize exceptionally well, which is a process that increases wear and corrosion resistance while improving the appearance. 6063 anodized extrusions are primarily utilized in architectural applications such as window frames, curtain walls, and pieces of external decorative trim due to their aesthetically appealing nature.
• High resistance to tensile stress: 6063 alloy with heat treatment (T5 or T6 temper) gets to 35,000 psi (T6) of tensile strength which guarantees durability and structural integrity. In construction and infrastructural development, this is particularly useful for load bearing parts.
• Ease of Use in Sophisticated Designs: The alloy can be extruded in complex shapes, which can be manufactured consistently and accurately, improving material efficiency and design. This versatility promotes various uses in aerospace, automotive, industrial manufacturing, and other sectors.

Such attributes boost the dominance of 6063 aluminum alloy in extrusions. Offering a combination of functionality, eco-friendliness, and economy that is essential for contemporary engineering and architectural design challenges.

Where is 6063 Aluminum Used?

6063 aluminum finds its application in industries that need good resistance against corrosion, well-developed mechanical features, and a pleasing surface finish. For example, in architectural constructions, its desirable and aesthetic features make it suitable for use in window- and door frames, as well as in curtain walls. Furthermore, it is also found in transportation parts, as well as in heat exchangers and pipe fittings where light weight and strength are predominant factors. This makes it highly useful in residential and industrial construction.

6063 and 6061: How Do They Compare in Aluminum Extrusion?

Comparing Mechanical Properties

6063 and 6061 alloys differ primarily in strength, corrosion resistance, and ease of machining.

• Strength: 6063 has lower tensile and yield strengths than 6061, which is better for structural applications where load-bearing capacity is vital.
• Corrosion Resistance: Both alloys are reasonably resistant to corrosion, but 6063 is more favorable in cases where surface quality and weathering resistance are important, such as in architectural applications.
• Machinability: Due to its composition, 6061 is more favorable for machining and welding, thus, it is more useful in precise and intricate work.

Which alloy is better depends on the specific application in question, balancing strength and appearance versus machinability and resistance to corrosion.

Corrosion Resistance: 6063 vs 6061 Aluminum

In investigating the corrosion resistance of 6063 versus 6061 aluminum, their compositions and applications must be taken into account. Both alloys fall under the 6xxx series which is known to resist corrosion because of the presence of magnesium and silicon. Still, in certain environments like weather and surface finish exposure, 6063 is claimed to have more corrosion resistant properties than 6061.

Due to the increased resistance to surface oxidation when compared to 6061, 6063 aluminum is more often employed for architectural applications such as exterior facades, window frames, and any other structures that are frequently exposed to moisture and different weather changes. Studies indicate that 6063 has surface quality that permits a natural protective oxide layer to be formed which boosts its durability in such conditions.

On the other hand, in spite of offering good corrosion resistance, aluminum 6061 is somewhat more susceptible to pitting corrosion in chloride environments such as coastal areas and places with saltwater exposure. Nonetheless, it is more widely used for structural work in aerospace, automotive, and marine industries, which require strength and moderate corrosion resistance due to its increased versatility and greater tensile strength. Anodizing and other treatments can further enhance the corrosion protection of the alloys, but these treatments are most beneficial to 6061 when its aesthetic appeal is of secondary priority.

Determining the corrosion behavior of these alloys in certain conditions is essential for the correct choice of the materials, taking into account the expected operating life, strength and surface finish.

Evaluating Weldability and Machinability

In terms of weldability, 6061 aluminum alloy tends to rank higher due to having stronger weld joints with proper post-weld heating as compared to 7075. The welds formed in the 7075 tend to have lower strength which makes it not very suitable for welded structures that are critical.

As for machinability, both alloys 6061 and 7075 have outstanding ratings. For general machining, 6061 aluminum is the alloy of choice as it is easier to cut while causing less wear on tools. 7075 aluminum, however, is more precise for machining but its greater strength and hardness may lead to quicker tool degradation, thereby requiring the use of more advanced cutting tools. Proper selection of the parameters and tools increases machinability for specific applications.

Choosing the Right Aluminum Alloy for Your Extrusion Application

Factors to Consider in Aluminum Extrusions

While selecting an aluminum alloy for extrusion applications, the following important components should be considered:

Strength Requirements

• Determine if there is a minimum load-bearing value for the application. Advanced options like 7075 and its higher 7075-T651 are stronger but may be overkill in non-structural applications, where 6061 would do just as well.

Corrosion Resistance

• If the extrusions will be used in harsh weather or damp conditions, an alloy with improved corrosion resistance, like 6061, should be preferred.

Machinability

• Determine the possibility of other operations besides extrusion. Alloys like 6061, which are easier to process, cause less tool wearing and make processing easier.

Weight-to-Performance Ratio

• Determine the degree of lightweightness versus performance. The alloy considered should meet both functional and economic requirements.

Cost Efficiency

• Compare the costs of different alloys and examine their selection relative to the predetermined cost and performance expectations.

Considering all the above factors will ensure that optimal performance is distinctly achieved from the chosen alloy for specific extrusion applications.

6061 or 6063: Which Alloy is Suited for Your Needs?

Selecting between 6061 and 6063 is circumstantial and depends particularly on the application in question:

• 6061 is the best fit for projects needing high strength, durability, and versatility. It has good structural support capacity, is corrosion resistant, and is machinable. It is frequently used in aerospace, automotive, and industrial fields.
• 6063 optimally suits projects where aesthetics, surface smoothness, and quality of extrusion are of utmost importance. This alloy is frequently used in windows and other architectural components and trims because of their good degree of corrosion resistance.

6061 is the best option when superior structural performance is needed but 6063 is the better choice for designs focusing on visual appeal and accuracy of extrusion.

Consulting with Aluminum Suppliers

Making arrangements with reputable aluminum suppliers is vital for ensuring the material suits the application requirements while picking the ideal aluminum alloy for a project. Suppliers share crucial information regarding an aluminum grade alloy’s mechanical properties, the available grades, and the processing options. For example, they can advise if the roughly 45,000 psi tensile strength of 6061 aluminum would be adequate for your structural needs, or whether the better tensile strength of 6063 around 27,000 psi would serve your projects superior extrusion characteristics better.

Moreover, aluminum suppliers can offer surface finish data, corrosion resistance, and thermal capabilities, which are essential for harsh operational or environmental applications. As suppliers share crucial information to help optimize production workflows, they assist in locating aluminum parts and components that match the target price so they can reveal manufacturing efficiencies like extrusion possibilities or machining needs.

If utilized early in the project development phase, suppliers enable customizations like potion size and alloy tempering to meet specific tolerances. Reliable suppliers usually have the corresponding documentations and certifications which is a guarantee of quality and compliance with the industry as well as aiding to avert material mismatch and making the entire project more efficiently.

How is Extruded Aluminum Commonly Used?

Popular Extrusion Applications of 6061 and 6063

The 6061 and 6063 aluminum alloys are especially popular for use in extrusion because of their strength-to-weight ratio, corrosion resistance, and versatility. Components that need a lot of mechanical strength, like beams, framing systems, and parts of the aircraft, can be made using 6061. 6063, having better surface finish and anodizing capabilities, is more suitable for architectural applications like window and door frames and other decorative trim uses. Both alloys have strong mechanical properties, which, combined with their ease of manufacturability, makes them extensively employed in the construction and transportation industries.

The Architectural Uses of 6063 Aluminum

6063 aluminum is nothing short of impressive in its use for architecture and construction, considering its mechanical properties, aesthetic application, and how well it can be processed. This is one of the metals that modern construction and design prefers because of its excellent corrosion resistance along with outstanding surface finish. One of the major uses includes the fabrication of window and door frames, as it offers precision alongside complex shape retention, which guarantees airtightness and durability regardless of how the weather may change.

6063 aluminum is now extensively utilized in the fabrication of curtain wall systems which are lightweight non-structural walls that are used in skyscrapers at high altitudes. The strength of this alloy is complemented by its compatibility with anodizing for custom finishes like matte, brushed, or colored coatings that add to the visual appeal of a structure.

Aside from aesthetic design, its configuration allows for thermal conductivity that makes it easier to dissipate heat energy, making it useful for energy-efficient designs. Information reveals that its outstanding strength-to-weight ratio, alongside high recyclability, makes sustainable construction easier by reducing the material cost and environmental impact. With all the benefits coupled with adaptability, it is no wonder why it is the most sought-after material in the world of architecture.

6061 Aluminum in the Aerospace Industry

6061 aluminum dominates the aerospace industry thanks to its remarkable strength-to-weight ratio, corrosion resistance, and ease of machining. This alloy is commonly used in aircraft structural components such as frames, wings, and fuselages, which need to be strong and durable. Its high strength and ability to endure varying temperatures make it applicable in commercial as well as military aircraft. Also, having superb weldability and suitability for various other manufacturing techniques makes this alloy versatile, ensuring stringent performance requirements are met while guaranteeing rapid production cycles.

Frequently Asked Questions (FAQs)

Q: What are the main differences between 6061 and 6063 aluminum alloys?

A: Differences between 6061 and 6063 aluminum alloys result from their constituents and the alloys’ characteristics. 6061 is mostly combined with magnesium and silicon, which gives it higher strength and better machinability. For that reason, it is usually employed in structural works. In contrast, 6063 is well known for its superb extrudability and good aesthetic finish. It is mostly employed in architecture and in custom aluminum extrusions where the visual side of the products is essential.

Q: Which alloy is better for custom aluminum extrusions?

A: Both 6061 and 6063 aluminum alloys can be utilized in custom aluminum extrusions, but in this case, 6063 is usually preferable. 6063 yields better extrusions, which makes it feasible to obtain more intricate designs with finer surface finishes. It is the most widely used of all the alloys for architectural extrusions, sign frames, and other applications where beauty is more important. However, 6061 is better when greater strength is necessary for custom extrusions.

Q: How does the strength of 6061 compare to other alloys of aluminum?

A: When discussing aluminum alloys, 6061 is known to be moderately strong compared to some other alloys. It has a reasonably good combination of strength, resistance to corrosion, and ease of machining. 6061 alloys are more powerful than 6063 and several other alloys in the 6000 series, yet are not as powerful as some in the 7000 series. This strength, along with favorable workability, has made it a material of choice for structural, marine, and automotive applications.

Q: What are the most common applications for 6063 aluminum extrusions?

A: The primary reason why 6063 aluminum extrusions are easily adopted for numerous applications is their impressive extrudability combined with an appealing surface finish. A few of these applications are: 1. Framing for architecture (windows, doors, curtain walls) 2. Sign frames and display cases 3. Hardware for lighting 4. Furniture 5. Rail and fence building 6. Enclosure for electrical devices 7. Cooling fins It is widely accepted in these applications because of the good surface finish, ease of corrosion, and the ability to be extruded into detailed shapes.

Q: What is the difference in welding aluminum extrusions between 6061 and 6063?

A: Both aluminum alloys 6061 and 6063 are said to have good weldability, but 6061 is usually considered to be better in welding operations. 6061 has better strength after being welded and does not crack as much during the welding operation. Still, 6063 is weldable and is often used where welding is needed. The decision of which to use for welded aluminum extrusions, however, may rest on other factors pertaining to the application, like strength requirements as well as finishing after welding.

Q: Which alloy for aluminum extrusions is more widely accessible in the marketplace?

A: For aluminum extrusions, 6063isis is the most commonly available alloy in the market. It is the most commonly used aluminum alloy for extrusion processes because of its excellent extrudability and versatility. , which is also readily available and commonly used, is the second most used aluminum alloy for extrusions. Because 6063 is widely used in architectural and ornamental uses, it is available in greater quantities in the extruded form.

Q: Are 6061 and 6063 aluminum alloys weldable and brazable?

A: Yes, both 6063 and 6061 aluminum alloys can be welded and brazed. These alloys are often used in custom fabrications because of their attractive combination of mechanical properties and capability to be welded. Their weldability increases their use in custom aluminum extrusions as well as other applications needing certain strength properties.

Reference Sources

1. Examination of the Effect of Cooling Rate after Extrusion to Formability of 6061 Automotive Profiles. 

• Authors: A. Vazdirvanidis et al.
• Published: March 15, 2023
• Journal: Applied Sciences
• Key Findings: 
• The study aims to analyze the effects of various cooling methods (water quenching, air cooling, and step-cooling) post-extrusion on the mechanical properties and microstructure of 6061 aluminum alloy profiles.
• It was observed that rapid cooling improves formability due to enhanced differences in microstructure through varying mechanical performance.
• The results of this study demonstrated that the methods of cooling should be given more attention to in order to optimize the production process for automotive parts.
• Methodology: 
• The authors conducted microstructure examinations post-artificial aging and performed mechanical testing (three-point bending and tensile tests) to assess the formability differences among the cooling methods.
• Analytical techniques were electron fractography and grain boundary misorientation analysis (Vazdirvanidis et al., 2023).

2. Comparación y Efecto del Homogenizado en Billets de Aluminio AA 6063. 

• Authors: Bladimiro Hernán Navas Olmedo. H. Moscoso
• Published: February 11, 2018
• Key Findings: 
• This paper analyses the effects of homogenization on AA 6063 aluminum billets obtained through horizontal continuous casting and vertical semi-continuous casting.
• The study highlights the need to pay attention to proper homogenization in order to achieve proper uniform chemical composition and mechanical properties that are vital for extrusion.
• Methodology:
• The impact of homogenization on hardness and overall quality was evaluated through metallographic techniques and was accompanied by the quantification of alloying elements through spectrometric techniques (Olmedo & Moscoso, 2018, pp. 322–331).

3. Characterization of Microstructural Refinement and Hardness Profile Resulting from Friction Stir Processing of 6061-T6 Aluminum Alloy Extrusions

• By:  N. Netto et al.
• Published: July 19, 2018
• Journal: Metals
• Key Findings:
• The issue undertook the study of the changes in the microstructure and hardness profiles for the extrusions of 6061-T6 aluminum alloy subjected to friction stir processing.
• This led to a remarkable refinement of the microstructure, in turn leading to enhanced hardness and other mechanical properties.
• Methodology:
• Netto conducted microhardness tests and microstructural analysis to determine the degree to which friction stir processing altered the 6061-T6 alloy’s structure and properties (Netto et al., 2018).

4. Aluminium

5. 6061 aluminium alloy

6. Leading Aluminum Extrusion Machining Provider in China