Welding Aluminum can be very difficult as it requires good knowledge of the TIG to be used and because the material is soft and highly sensitive, it requires different techniques and processes than steel to be welded successfully. Even for experienced welders, welding Aluminum can be quite challenging because of the different techniques involved in the welding process of Aluminum. The popular inert gas fraction used in melting Aluminum is 75 helium and 25 Argon, but on the other hand, welders have tried exploring using 75 Argon 25 CO2 for its welding process, hence, can 75 Argon 25 CO2 be used to weld Aluminum?
Welding Aluminum with 75 Argon and 25 CO2 is not advisable because it will cause a mess. As known, Aluminum is a soft and sensitive material, and welding it with CO2 present in the inert gas mix can cause the Aluminum material to be damaged. Instead, you can use a mix of Argon and helium.
Choosing the inert gas mix to be used while welding Aluminum is a major choice to be made. In this article, I’ll explain the reasons why you can’t weld Aluminum with 75 Argon and 25 CO2, and other gases that can be used to weld Aluminum.
Why You Can’t Weld Aluminum With 75 Argon And 25 CO2?
Aluminum cannot be welded with 75 Argon and 25 CO2 because CO2 is very reactive to Aluminum. Due to the kind of material Aluminum is, CO2 will react with it and cause the welding process to be messy and unsuccessful.
Aluminum is a soft and highly sensitive material that requires pure inert gases to be used while melting the material. Although CO2 is an inert gas, its reactivity with Aluminum causes it to be a bad choice to be used as a mixture with Argon to weld Aluminum. Aluminum has a great affinity for oxygen and when it’s welded with a mixture of Argon and CO2, it results in creating its oxide (Aluminum oxide).
The best choice of the inert gas mixture to be used while melting Aluminum is 75% helium and 25% Argon or Vice versa. Both inert gases make a better mixture and have less reactivity with Aluminum hence causing the welding process to be successful.
You can also use pure Argon for the welding process of Aluminum. This inert gas works because it has low reactivity with Aluminum and cannot cause the material to be damaged. Pure Argon is the most popular shielding gas used by welders while welding Aluminum.
What Other Gases Can Be Used To Weld Aluminum?
Shielding gas is important while welding Aluminum. Most times, the selection of gas is driven by ease of use, cost, and heat-input needs. The thermal conductivity of Aluminum is high hence, there’s a need for high heat input while welding thicker parts of the Aluminum material.
Pure Argon has been proven to be the most popular and effective inert gas used as a shielding gas while welding Aluminum. Aluminum does not have a great affinity for Argon hence, the ease it brings while using it to weld the material.
Moreso, a mixture of helium and Argon can be used as shielding gas for welding Aluminum. Usually, the advisable ratio of the inert gases to be used while welding Aluminum is 75% helium and 25% Argon or Vice versa. Helium and Argon are both inert gases with Aluminum having a low affinity for both gases hence the low reactivity between Aluminum and the gases thereby producing a smooth welding process.
The downside of using the helium and Argon gas mixture is the high cost of helium. Although the demand for helium grows steadily, the worldwide availability of the product grows thinner thereby causing an increase in the cost to acquire the gas.
A better option that can be used in the mixture instead of helium, is nitrogen. Using nitrogen helps you get the benefits of helium without worrying about the cost. Only a small fraction of nitrogen is needed with the Argon to create the perfect replacement shielding gas for welding Aluminum, with lower costs.
Aluminum nitride is created when Aluminum is added with nitrogen. Aluminum nitride is very emissive because the surface efficiently emits thermal energy hence delivering the same results required when you use helium blends. All of these are also done at a lower cost compared to helium.
How To Weld Aluminum?
Welding Aluminum requires getting The right welding process as many tools and welding processes out there are designed for welding steel.
Before initiating the process, you must clean the Aluminum thoroughly to avoid any contaminations in the process of welding the material because Aluminum is very prone to impurities. The following are the steps to follow to weld Aluminum:
Step 1: Clean The Aluminum’s Surface
Make sure to use a solvent like a mild alkaline solution such as soap, or acetone to remove any oil, grease, and water vapor from the Aluminum’s surface. Remove the surface oxides with a stainless wire brush. On the other hand, you can also use strong alkaline or acid. After cleaning, always keep your Aluminum dry and stored at room temperature, and make sure to weld it within days of cleaning.
Step 2: Wear Protective Equipment Before Welding
Safety is very important in welding as there are a lot of hazards that are generated in the process of welding. Always ensure to wear proper protective equipment that includes goggles, safety glasses, welding helmets, welding coats, and factory boots. Do not forget to wear gloves to protect you from metal splatters and sparks. Make sure the room has enough fume ventilation to help keep the fumes out of your air.
Step 3: Choose The Right Inert Gas
As explained earlier, you have a list of inert gases to choose from and use as shielding gas. They include Argon, helium, and nitrogen. You can weld with pure Argon as the shield gas or a mixture of Argon and helium or nitrogen.
Step 4: Begin The Welding Process
Set up your TIG and begin welding the Aluminum. Remember you need to be careful as Aluminum is a soft material to avoid damaging the material.