The pursuit of increased efficiency has become a sign of the 21st century. To achieve an increase in these indicators, the widespread use of composite materials, the development of powder metallurgy and the introduction of aluminum alloys into the production cycle began.
The high cost of this material relative to steel greatly inhibits this process. However, little by little, aluminum is replacing traditional materials.
The flagship in the use of aluminum is the aircraft industry, which needs the lightest possible parts. But already in the latest car models this material is widely used. To create a solid piece, aluminum, like steel, is welded.
Aluminum alloys and pure metal can be used for the production of a welded part.
Non-heat-hardening alloys are considered the most suitable for these works.
These include the following types :
- Technical aluminum
- Manganese (Mn) based alloys
- Magnesium alloys (Mg)
Welding of heat-strengthened alloys is fraught with great difficulties, therefore, if possible, avoid it.
Difficulty welding
The main problem in welding is the formation of aluminum oxide during operation.
It has a high melting point of 2050 degrees.
This oxide reduces the quality of the seam by forming a film on the surface. To neutralize this effect, cathode sputtering is used in the work. Alternatively, a flux can be used.
At high temperatures, the metal loses its hardness.
Aluminum has a high fluidity, so it is more convenient to work in the lower position.
The mechanical properties of this metal are such that it has the property of deformation, especially magnesium alloys are prone to this. Therefore, special welding modes are used.
Of considerable difficulty is the appearance of pores in the weld metal, which worsen the mechanical properties of the product. To neutralize them, it is recommended to perform mechanical and chemical cleaning of the filler wire and metal surface.
Aluminum has a high thermal conductivity - welding requires the use of powerful energy sources. In some cases, preheating to a temperature of 150 degrees is required.
During the welding process, cracks can occur due to changes in the crystal structure.
To prevent this effect, elements that reduce the possibility of cracking are placed in the weld pool.
Gas welding
To improve the quality of the seam, you can use inert gases in the work. These can be argon and helium.
Welding in these gases is performed with non-consumable (tungsten) or consumable electrodes.
There are 2 types of such electrodes :
- Ittrated
- Lanthanum
The use of such electrodes with a diameter of up to 6 mm is productive for welding metal up to 12 mm thick.
Manual welding with a tungsten electrode, performed on an AC machine. Gas consumption in this case is up to 15 liters per minute.
In order to increase productivity, welding can be carried out with a three-phase arc, in which case the metal thickness can be 30 mm.
Automatic welding
This type of work can be carried out on a layer of flux, and under it and is performed on a direct current of reverse polarity.
Automatic welding improves work efficiency, reduces material consumption .
You can choose reliable equipment at Oliver, which is the leader in the Belarusian market of welding equipment.
