How to Choose the Best Shielding Gas for Aluminum Welding

Date Posted:1 May 2023

Welding aluminium is a popular process in many industries, including automotive, aerospace, and construction. However, welding aluminium requires different techniques and materials than welding steel. One crucial aspect of welding aluminium is choosing the right shielding gas.

Shielding gas protects the weld from contamination and oxidation during the welding process. This article will discuss the different types of shielding gases used in aluminium welding and determine the best gas for the job.

Types of Shielding Gas

The most common types of shielding gas used in aluminium welding are argon, helium, and a mixture of the two gases. Argon is the most popular choice because it is inexpensive, readily available, and provides excellent arc stability.

Helium, on the other hand, is more expensive but can provide deeper penetration and faster welding speeds. A mixture of argon and helium can combine the benefits of both gases to produce a high-quality weld.

1. Argon Shielding Gas

Argon is a non-reactive gas, which means it does not react with aluminium during the welding process. It is an effective shielding gas because it provides a stable arc and good penetration.

Argon also produces a narrow and focused heat-affected zone, which helps prevent distortion and warping of the material. When using argon, welders typically use a flow rate of 20-30 cubic feet per hour (cf).

2. Helium Shielding Gas

Helium is a reactive gas that can interact with aluminium during the welding process. This can sometimes cause porosity and other defects in the weld. However, helium provides deeper penetration than argon, which can be useful when welding thicker materials.

Helium also has a higher heat input than argon, which can result in faster welding speeds. Welders typically use a flow rate of 50-60 cfh when using helium as a shielding gas.

3. Argon-Helium Mixture

A mixture of argon and helium can provide the benefits of both gases. A typical mixture is 75 per cent argon and 25 per cent helium. This combination can provide good penetration and arc stability while also increasing welding speed. Welders typically use a flow rate of 30-40 cfh when using an argon-helium mixture.

Choosing the Best Shielding Gas

When choosing the best shielding gas for aluminium welding, several factors need to be considered, including the thickness of the material, the welding position, and the desired welding speed.

Argon is usually the best choice for thinner materials because it provides good penetration without causing too much heat input. For thicker materials, a mixture of argon and helium can provide the necessary penetration while also increasing welding speed.

The welding position is also an important consideration. Generally, welding in the flat position requires less penetration than welding in other positions. Therefore, argon may be sufficient for flat-position welding, while an argon-helium mixture may be necessary for overhead welding.

Conclusion

Choosing the right shielding gas is essential for producing high-quality aluminium welds. Argon is the most popular choice because it provides good arc stability and penetration without causing excessive heat input. Helium can be useful when welding thicker materials, but it can also cause defects in the weld if not used correctly.

A mixture of argon and helium can provide the benefits of both gases and is a good choice for welding thicker materials or when increased welding speed is desired.

Ultimately, the choice of shielding gas depends on the specific welding application, and welders should consult with industry experts to determine the best gas for the job.

If you are looking for high-quality welding tools and supplies in Australia, look no further than National Welding and Industrial Supplies. Whether you are a professional welder working on a major construction project or a DIY enthusiast working on a hobby project at home, we got everything you need to get the job done right. Shop with us today!

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