Aluminum Fabrications

Aluminium fabrication is a challenging task indeed. The special properties of aluminium often pose some serious challenges even to the most experienced welders. For example, aluminum is a very well conductor of heat. At the same time, it has a low melting point. Naturally, it becomes difficult to weld the aluminium sheet without burning at least some portions of it. Also, there are some impurities involved in the aluminium which is important to be got rid of. At the same time, one should preheat the aluminium sheet to ensure that the welding is done properly without any chance of cracks.

Regarding all these actions, the push technique is often considered preferable for the experienced professionals. This is basically the technique pushing the gun away from the welding puddle instead of pulling it towards it. The process ensures better cleaning actions, improved shielding gas coverage and reduced weld contamination. Anyways, it is important that the entire welding is done quickly. Since the thermal conductivity of aluminum is high, you need to use higher voltage and amperage settings. Also, you have to have high weld travel speed to ensure that the work is done during the right temperature.

When it comes to shielding gas for aluminum welding, the argon is the most popular option. This is largely because of its ability to clean and penetrate. However, if someone is welding 5XXX series of aluminum alloys, the use of a mixture of argon and helium is preferred. This will reduce the formation of magnesium oxide in the welding process.

Another tricky task for aluminum welding is to select the welding filler wire. Ideally, you should pick up a wire that has a very similar melting point to the base material. This is crucial, the narrower the gap between the filler and the base material, the easier the process will be. Also, you should prefer a wire with a large diameter.

One of the greatest challenges with the aluminum welding is the crater cracking. In fact, this is the most common factors that cause failure in aluminum welding. The crack occurs largely because of the higher rate of thermal expansion of aluminum. However, the risk is even greater when you are welding the concave craters as their surface tears at the time of contraction. Therefore, the welder must ensure that a convex or mound shape is developed during the welding. This will compensate the amount of contraction at the time of cooling down. Finally, you should always choose the power source tool according to the method of transfer spray arc.