It is a known fact that welding aluminum can present a high level of difficulty for the welder. Welders must follow specific guidelines if they wish to weld aluminum with a degree of success. The reason for this is that aluminum has both a lower melting point and a higher thermal conductivity than steel. The aluminum welding techniques we discuss below will help ensure success for welders who are struggling to deal with aluminum.
First, welders have to make sure that they clean the base material and also remove any hydrocarbon and oxide contamination from either cutting solvents or oils. This is known as base-metal preparation. Then, operators have to look toward proper preheating. Proper preheating is done to make certain that the weld does not crack. This is done by simply preheating the operator’s aluminum workpiece.
The next aluminum welding technique we'll discuss today is the push technique. The push technique demands that the welder pushes his gun away from his weld puddle instead of pulling it. This simple change in technique should result in three important advantages. It will result in improved shielding-gas coverage, reduced weld contamination and superior cleaning action.
Another of the aluminum welding techniques that operators should keep in mind is speed. Aluminum welding must be performed in a way that is fast and hot.
Having the right kind of shielding gas during aluminum welding helps a great deal. It is recommended that argon gas be used as the shielding gas during aluminum welding. The reason for this has to do with both its favorable penetration profile as well as its effective cleaning action.
Choosing the right welding wire is integral to the success of aluminum welding. Operators should choose an aluminum filler wire whose melting temperature is close to the base material.
During welding, operators have to feed in the aluminum wire. A lesser known aluminum welding technique is for welders to employ the push-pull method when feeding the soft aluminum wire for long distances. This method uses a wire-feed cabinet that is enclosed. This shields the wire from the surrounding environment. It is also recommended that welders utilize a distinct gun liner when they weld aluminum.
If welders are worried about being able to successfully deliver a wire-feed rate that is even, they need to think of drive rolls that are developed particularly for aluminum. This way, the drive roll tension may be set in such a way that it avoids excess tension, which creates erratic and rough feeding, and inadequate tension that results in uneven tension.
Finally, welders ought to utilize a contact tip that’s about 0.015 inches bigger than the diameter of the filler metal, which is being used. As this contact tip heats up, it will expand into an oval shape and then potentially limit the feeding of the aluminum wire.
With these several aluminum welding techniques, operators should get a good idea of what to do in order to achieve successful results with aluminum welding. Sometimes a difficult welding material to deal with, aluminum can give the average welder problems if he does not stick to the above guidelines. Due to its lower melting point and greater thermal conductivity than steel, aluminum is a challenge for welders.