Aluminium is a non-ferrous metal with a low density of 2.7 g/cm3 and forms 8% of the Earth’s crust. Welding aluminium is crucial because of its provision of engineering materials with a strong bond and at a reasonable price of transportation. Finding the best procedure of aluminium welding can be challenging based on its size and the methods used. The three fundamental aluminium welding techniques include Mig, Tig, and spool gun welding.
MIG welding technique
Mig welding is the most typical procedure and smart way of welding aluminium. The method involves using a constant wire feeding to aluminium on the welding region. The progressive wire fed ensures free hands welding, improves the quality of the weld, speed, and ease mechanization. The method makes safeguard the possibility of welding alloys with 1mm thick and above depending on the power supply from the Mig welding machine.
The technique provides thinner aluminium with the spot weld preventing them from blowing. The lesser sized wire employed in the process helps in finer operations of welding the metal. Accordingly, welding wire with 0.9 mm has a capability of welding metal sheets with their size ranging from 1 mm-2.5 mm. There are various factors to ensure a successful welding process.
Considering the material thickness:
The thickness of the material is the primary factor considered when carrying out the welding process by the MIG technique. The capacity of production determines the welding thickness, including materials with 14 gauge. Notably, it is imperative to use thick wire in welding aluminium to prevent destructions by high voltage resulting from an increased supply of electricity.
Maintaining the material clean:
Thorough cleaning of aluminium is necessary before the welding process. It involves removing any lubricants available in the material to be welded. Elimination of oxides is also carried out, especially after degreasing with either stainless cup or hand wire brush. Keeping pressure and rpms low helps in preventing the surface of the material used from smeared by entrapping impurities and oxides under the cover. So, an aluminium wire brush is always the best alternative in cleaning to avoid contamination of the base material.
Consider the welding process used:
Spray transfer is the best mode used during MIG welding aluminium. The process involves smooth transferring of droplets contained in the molten metal from the electrode end to the molten pool in which the droplets passing the arc material have a small diameter than that of the electrode. The spray transfer has less short-circuiting with relatively high efficiency and deposition rate.
However, welders should be aware that a high amount of heat by spray transfer leads to the formation of a large pool of a weld with the perfect penetration with brutal control measures. Therefore, it is essential to avoid using spray transfer for welding thinner materials than 14 gauge.
TIG procedure for aluminium welding
Tig is the next method used in welding aluminium. The application of the technique is challenging and requires training by a welder to gain skills in using the method. The system involves heating the actual aluminium to the melting point using a tig welding torch. The procedure also requires the presence of a filler rod appropriately to affect the production of welding beads.
Good mastery of the usability of Tig machines is the best achievement since the procedure requires artwork operations. Notably, it needs a reasonable expertise level in allowing the finished weld to attain 1/16 inches broad. Additionally, the addition of the filler into the process helps in creating a preventive atmosphere in the procedure. There are tips on how to enhance efficiency in Tig welding.
Using the appropriate polarity:
Polarity is one of the best tips applied in welding aluminium. The system requires welders to employ an alternative polarity current in the process of welding. The flow of current allows directional change continuously throughout the operation. Additionally, polarity helps in cleaning the weld, and removal of the oxide layer formed on the aluminium for visibility of the molten pool becomes of a weld.
Adjustment of the balance control:
The process involves setting the proper control balance contributing to a solid weld of aluminium. With the alternative current polarity, the weld contains both positive and negative electrodes potions in the system. The negative electrode involves the waveform part used to handle the welding while the positive electrode consists of the cleaning part used to remove the oxide. Therefore, the balance control specification facilitates ratio adjustments between t2 wavelengths on the weld puddle and the demerits of oxidation in the cycle.
Frequency of the AC output:
Setting the AC output frequency is an essential factor that enables simple weld placement. The system can be adjusted and placed on the power source of the welding power. Accordingly, the output frequency indicates the number of times the electricity source switches polarity in each second. Seemingly, the higher the output frequency increases the stability of the arc, providing much directional regulation, thus allowing tight welding without arc wandering.
Make protection apriority:
The process requires welders to wear proper personal safety equipment to prevent them from injuries. The protective equipment includes a welding jacket, welding helmet, gloves, and safety glasses. Since it is difficult to perceive clearly during welding aluminium, welders must purchase a new helmet with high technology to improve clarity and visibility of a weld pool. The technology allows for the contrast of many colours of the object in the welding region hence leads to better achievement of results and reduction of eye fatigue and strain.
Welding aluminium with a spool gun
The spool gun the third method used in welding aluminium. The application of the procedure is necessary for feeding the soft wire of aluminium through the liner. Additionally, the spool gun enables feeding of the wire for a few inches of the liner with a length of 8-10 feet on the welding area.
The process involves loading 1 pound of aluminium wire spools in a small gun consistently since the spool gun is less maneuverable hence making operation worth. There are various tips for improving the welding operation with the spool gun.
Push the gun angle:
The puddle pushing with 10-15 degrees is necessary for enhancing the welding operation. Pulling is not essential since it leads to the production of a sooty weld hence reducing the quality of aluminium. Additionally, pulling can cause trapping of the oxides into the puddle during welding,thus leading to the production of the porous welds.
Cleanliness of the metal:
Cleaning old metals used for welding is crucial in removing the oxidation of a thick layer formed on the metal to obtain better welds. The oxidation removal involves wire brushing using a stainless brush wire or abrasive wheel that leaves no residue on the metal surface. Notably, the abrasive wheel is useful in aluminium with heavy oxidation followed by acetone for wiping.
The process involves using a flowmeter in controlling the rate of gas flow during the welding process. It is critical to regulating the amount of gas flowing since too much flow can lead to wastage, thus reducing the quality of the weld. However, the nominal flow rate of the gas can lead to the production of sooty weld that may be difficult to clean.
Welding aluminium is an essential process of improving its quality for effective operation. Therefore, for practical welding, welders require to follow the procedures as discussed comprehensively and understand them before choosing the method given that each method contains merits and demerits.
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What environment is suitable for Aluminium welding?
The best environment for Aluminium welding is a region covered with sand to prevent an explosion when heating occurs.
Do all welders applying TIG weld Aluminium?
Not all, only alternative current TIG applicable in welding Aluminium.
What is the polarity for Aluminium welding?
Alternating. In the positive period cleaning the metal surface occur, which is crucial for the welding process. Alternately, in the negative period allow more heat into the pool used in welding