A high-strength alloy, 5XXX aluminums are easily welded. Components made with this material, such as auto parts and plates, are strong and durable. 6XXX is a close runner up. While the most common aluminum alloy used in welding, it can crack when exposed to extreme heat for too long.
A: A common aluminum alloy, 6061-T6 is welded every day, so we assume it must be easy to weld. Unfortunately, it isn't. In fact, 6061 and the other 6XXX series alloys are relatively sensitive, and it isn't uncommon for people to have cracking problems with them.
5XXX and 6XXX series aluminum alloys are the best for welding overall.
2000 Alloys:
They are extremely sensitive to hot cracking and are the least weldable aluminum alloys. Specifically, 2024 is the least weldable. But there are a couple exceptions, 2219 and 2519, which can be readily welded with 2319 or 4043 filler metal.
TIG welds are better for thinner metals and smaller projects because they produce precise and clean welds. MIG welds work well with larger projects with thick metals that need longer, continuous runs. Control: TIG welders need to have experience with timing and balancing materials in both hands.
However, the same traits that make aluminum desirable can also make it tricky to work with. So why is aluminum so difficult to weld? This material is soft, highly sensitive and is insulated by a tough oxidized layer. While in its molten state, aluminum is susceptible to impurities, which can lead to porous, weak welds.
Material thickness: Most reputable MIG machines can be used to weld aluminium down to 3mm thickness. To successfully weld materials thinner than 3mm, it may be neccessary to use specialist MIG or TIG welders with pulse capability. (Note: to TIG weld aluminium, you will need an "AC/DC" machine such as the 202T).
Generally speaking, aluminum's capacity to be welded (weldability) varies between different alloy series. It can range from “very good” to “unweldable by common arc welding methods.” That said, most aluminum alloys can be welded under the right conditions and by taking proper precautions.
Using an instant adhesive or super glue is arguably the simplest and most hassle-free alternative to welding. As previously discussed in our Guide to Gluing Metal, we recommend an epoxy glue for a stronger bond.
Aluminium alloys pose a range of difficulties when welding, including: High thermal conductivity. This results in excessive dissipation of heat, which can make welding difficult and/or result in unwanted distortion of the parts, owing to a larger heat input being required. Hydrogen solubility.
Article Revised July 28th, 2022. It's often said that aluminum is a more difficult metal to weld than steel. While it's true that most welders start out by learning to weld steel before moving on to aluminum, it's not entirely accurate to say that one is more difficult than the other.
The thickness of aluminum in industrial welding applications typically ranges from 1/8 inch to 16 gauge, but you may be welding up to 3/8 or 1/2 inch in some cases. Gas and filler metal selection, as well as proper technique, may differ depending on the material thickness and the goals of the application.
Furthermore, the correct filler material must be selected. For instance, welding a 6061 alloy with a 6061 filler metal will result in weld failure. Instead, a 5356 or 4043 aluminum filler metal should be used when welding a 6061 base material.
Aluminum 5052 has a smoother finish than 6061, although it is not heat-treatable. Aluminum 5052 has a higher fatigue strength and modulus of elasticity than Aluminum 6061, making it an excellent forming alloy. Additional aluminum alloy 5052 characteristics include: Non-heat treatable.
A Comparison of 6063 and 6061 Aluminum Alloy
If strength is a primary consideration, 6061 may be the better choice. However, when it comes to surface quality, corrosion resistance and workability, 6063 performs better. Both these alloys are weldable, but it should be noted that 6061 is slightly more machinable.
7075 Aluminum
7075 is notable for its high strength-to-weight ratio and improved strength over 6061. Because of this, 7075 is largely used in aerospace, marine and transportation industries. Any industry where high strength and light weight properties are critical, this alloy is preferred.
Use a push angle instead of a drag technique. Increase the voltage to get into spray transfer. Use the proper base metal cleaning techniques, such as using a stainless steel brush. Check for proper shielding gas and wire alloy type.
Using a propane torch and some aluminum brazing rods is a quick way to bonding aluminum without using a welder. It makes for a very strong bond and with a little practice can be done quickly with great looking results.
Aluminum brazing is a popular method of joining two pieces of metal together, and for a good reason. It offers a strong connection between two pieces without needing to use a welding machine. In fact, aluminum brazing can create a joint that is even stronger than welding!
But TIG welding aluminum without a filler is extremely prone to cracking. Cracked welds fail tests. Worse, cracked welds that don't get tested cause projects to fail structurally.
Perhaps the most important thing to realize is that welded aluminum is generally weaker than the parent material. This is not true with other metals such as steel, which have welds just as strong as the original metal.
To achieve the best weld quality when MIG welding aluminum, you should use the push welding technique. Pushing the MIG welding gun away from the puddle instead of pulling it results in a better cleaning action, improved shielding gas coverage, and reduced weld bead contamination.
Through the process of arc welding, aluminum would be in a liquefied state by the time the steel begins to melt. Arc welding the two metals together would also create a brittle compound and would not create a strong fusion.
Can a gasless MIG welder be used to weld aluminium tubeing? No, aluminum MIG welding absolutely requires inert gas shielding. Pure argon is the most common choice. The gasless “MIG” process is only applicable to steel.