When it comes to welding, aluminum might not be the first material that comes to mind. However, this versatile metal can be welded with the right approach. Due to its lower melting point and higher thermal conductivity, welding aluminum requires a different technique than welding steel. If you’re planning a welding project with aluminum, choosing the right material is crucial for achieving successful results. So, how do you choose the best aluminum alloy for welding? Look no further, Taber Extrusions, has you covered!
To get a better understanding of which aluminum alloys are best for welding, let’s first define objectives and whether it’s necessary that the material is alloyed for the welding process.
Aluminum vs. Aluminum Alloy
Both pure aluminum and aluminum alloys can be welded using a variety of welding techniques such as tungsten inert gas (TIG) welding and metal inert gas (MIG) welding. However, it is important to note that welding pure aluminum can be more challenging than welding aluminum alloys due to its lower melting point, and higher thermal conductivity — which can lead to warping, distortion, and burn-through during the welding process.
Unlike pure aluminum, aluminum alloys are materials made by combining aluminum with one or more other elements to improve its mechanical, physical, and chemical properties. Some common alloying elements include copper, magnesium, silicon, zinc, and manganese. Aluminum itself has good properties such as high strength-to-weight ratio, corrosion resistance, and conductivity — but by alloying it with other elements — its properties can be further enhanced or customized to suit specific applications.
Weldability of Aluminum Alloys
Aluminum alloys are generally considered to be weldable, but the weldability can vary depending on the specific alloy and its composition. Some aluminum alloys are easier to weld than others due to their specific properties.
Here are some general factors that affect the weldability of aluminum alloys:
- Different alloying elements can significantly impact the weldability of aluminum alloys. For example, alloys with high levels of magnesium or zinc can be more difficult to weld due to their tendency to form brittle intermetallic phases during welding.
- The thickness of the material being welded can affect the heat input required to produce a successful weld. Thicker materials require more heat input, which can make it more challenging to maintain a consistent welding temperature and can increase the risk of distortion and cracking.
- Proper surface preparation is critical for achieving a successful weld. Aluminum alloys should be cleaned and degreased before welding to remove any contaminants that could lead to porosity or other defects in the weld.
- Welding technique can also impact the weldability of aluminum alloys. Tungsten inert gas (TIG) welding is generally considered the most suitable method for welding aluminum, but metal inert gas (MIG) welding can also be used.