6063 Vs 6061 Aluminum Extrusions: What Is The Difference?

Aluminum extrusions are essential in various industries, prized for their lightweight nature, corrosion resistance, and exceptional strength-to-weight ratios. Among the plethora of aluminum alloys, 6061 and 6063 stand out as the go-to materials for aluminum extrusions. On the surface, these two alloys may appear indistinguishable, yet they harbor distinct characteristics that critically influence their suitability for different applications. Understanding the differences between 6061 and 6063 aluminum extrusions is key to selecting the right alloy for your project needs. This article delves into the nuances of these two alloys, comparing their strengths, machinability, weldability, corrosion resistance, and typical uses to help you make an informed decision.

What Are 6063 Aluminum Extrusions?

6063 is a widely used aluminum alloy for extrusions. It is an aluminum-magnesium-silicon alloy, which means it has excellent corrosion resistance and good formability. 6063 aluminum extrusions have a smooth surface finish, making them ideal for decorative applications such as window frames, door frames, and trim.  It's also utilized in structural applications like solar panel frames and other renewable energy applications, as well as in the building sector.

Aluminum Construction Profile

What Are 6061 Aluminum Extrusions?

6061 aluminum extrusions are another widely used alloy for extrusions. It is an aluminum-magnesium-silicon alloy with good corrosion resistance and excellent mechanical properties. 6061 aluminum extrusions are commonly used for structural applications such as bicycle frames, aircraft parts, and automotive parts. Because of its resistance to seawater corrosion, it is frequently employed in maritime applications.

What Are The Differences Between Them?

Here are some differences between 6061 aluminum extrusions and 6063 aluminum extrusions as the following:

Machinability

Machinability refers to the ease with which a material can be shaped or formed using machining processes such as drilling, milling, and turning. In the context of aluminum alloys, both 6063 and 6061 are commonly used for extrusions and have different machinability characteristics.

6063 aluminum extrusions are known for their good machinability, especially when compared to other aluminum alloys. This means that they are relatively easy to machine using traditional machining techniques. Processes like drilling, milling, and turning can be performed smoothly on 6063 aluminum. However, one challenge that may arise during milling is the creation of lengthy, stringy pieces of aluminum. These long chips can cause issues such as chip clogging or poor surface finish if not properly managed.

On the other hand, 6061 aluminum extrusions also exhibit good machinability but are generally more difficult to machine compared to 6063 aluminum. When machining 6061 aluminum, shorter and more manageable chips are produced. These shorter chips are typically easier to handle and do not pose as many issues during the machining process. However, machining 6061 aluminum requires more cutting force and slower cutting speeds compared to 6063 aluminum.

Building Aluminium Extrusion

Weldability

6063 aluminum extrusions are known for their outstanding weldability. They can be easily welded using various welding processes such as TIG (Tungsten Inert Gas), MIG (Metal Inert Gas), and spot welding. This versatility in welding options makes them a popular choice for many applications. When subjected to welding, 6063 aluminum extrusions exhibit good resistance to weld cracking and porosity. 

On the other hand, 6061 aluminum extrusions also possess excellent weldability, but they require a bit more caution during the welding process compared to 6063 aluminum extrusions. When welding 6061 aluminum, especially using TIG welding, it is crucial to exercise extra care due to its increased susceptibility to hot cracking and porosity. Hot cracking is a form of cracking that occurs in the weld metal or HAZ when it is still hot, and it can be influenced by factors such as composition, welding parameters, and joint design. Porosity is also more likely to occur in 6061 aluminum when welded using TIG welding, meaning that extra attention must be paid to achieve high-quality welds. 

Corrosion Resistance

6063 aluminum extrusions are known for their excellent corrosion resistance, making them a popular choice in various industries. Compared to other aluminum alloys, 6063 exhibits superior resistance to corrosion. It performs exceptionally well in different environments, including atmospheric conditions, seawater, and industrial settings.

In terms of atmospheric corrosion, 6063 extrusions show remarkable resilience. They can withstand exposure to moisture, oxygen, and various airborne contaminants without significant degradation. This makes them suitable for outdoor applications where they may come into contact with rain, humidity, or pollutants in the air.

On the other hand, while 6061 aluminum extrusions also offer corrosion resistance, they are not as corrosion-resistant as 6063. They provide good protection against atmospheric corrosion, making them suitable for various outdoor applications. However, due to their vulnerability to saltwater corrosion, they are not recommended for marine applications. In environments with high salt content, such as those found in seawater, 6061 extrusions may experience accelerated corrosion, potentially compromising their performance and longevity.

Conclusion

In conclusion, while 6061 and 6063 aluminum extrusions both serve as excellent choices for a myriad of applications, they each bring unique properties to the table. They may share similarities in basic physical attributes like density and melting points, yet they diverge significantly in their mechanical strengths, flexibility, machining behaviors, and resistance to various forms of corrosion. The decision to use 6061 vs 6063 aluminum will ultimately hinge on the specific demands of your project, whether that's prioritizing structural integrity, aesthetic finish, or environmental resilience. For those in search of a reliable aluminum extrusion provider, XIANGZHEN stands ready to assist. Our selection encompasses a diverse array of aluminum extrusions, including the versatile 6061 and 6063, as well as the 6060 and 6065 series. Discover more about our products and how they can elevate your projects today.

* 6061 vs 6063