Aluminum is a unique type of metal that comes with its own set of challenges. It is not necessarily more difficult to weld than other metals, but its unique challenges mean that certain methods need to be used when welding. Here are some of the challenges that are associated with welding aluminum and how to address them.
Unstable Chemical Composition
Because aluminum has an unstable chemical composition, it can be easily broken up under stress. While welding, aluminum can easily react to the filler metal, which can lead to hot cracking, breaking, and brittle metal that will break later on. To avoid these issues, the welder should choose a filler metal that has a chemical composition with a lower sensitivity to heat and cracking.
Low Melting Point
Aluminum has a low melting point, making it more likely to warp, crack, and break during welding. In order to avoid these issues, the welder should use a GMAW process with pulsation capability. This process entails a power source combining a low background current and high break current into a rotational capacity to avoid excess heat or burn-through.
Discoloration
When welding aluminum, magnesium oxides can collect at the weld on the base of the material, leading to discoloration. For this reason, it’s important to use the right filler metal. Additionally, the welder should maintain the appropriate contact-to-work distance and hold the welding gun at the right angle. These precautions will ensure less buildup of the magnesium oxides and help prevent major discoloration.
Feedability
Aluminum wire is softer than other types of metal wires, making it more difficult to feed through a gun than other filler metals. In order to handle this wire, the welder might need a spool gun, push-pull gun, or MIG gun. The use of these tools will help reduce the chance of wire “birdnesting,” which is the tangling of the wire between the drive roll and liner.
CAMM Metals | CT Welding Services
In order to ensure your welding comes with minimal distortion, call in the professionals! As a CT welding contractor, we specialize in MIG & TIG welding of Steel, Stainless Steel and Aluminum and use Pulsed welding machines to help control the heat put into a part, minimize distortion, and improve the quality of the parts we produce.
After the welding is complete, we offer many in-house services. These services include, weld inspection with dye penetrant, acid cleaning and polishing of stainless steel welds. Additionally, we are also able to weld and test watertight enclosures.For those customers who require certified welds, we can certify our welds to AWS D1.1 & AWS D1.6.
