WELDING PROCESS 
WELDING PROCESS
CAN ALUMINUM BE WELDED WITH THE MIG/MAG PROCESS?
The answer is very simple: yes, it is possible. In fact, since the early development of the GMAW…
For the continuous wire process known as MIG-MAG, also called wire feed welding, setting the parameters requires properly stabilizing the arc; unlike the shielded metal arc welding process where parameter setting is simpler, as only a single parameter is adjusted — the amperage.
In the MIG-MAG process, different variables must be taken into account, and to achieve very good stability, the parameters must be set in a balanced manner to avoid defects that may occur.
The detachment of the droplet from the filler material (wire) to the base material can occur in different ways; these are known as transfer modes, and each transfer mode is obtained through different welding parameters, meaning voltage and amperage settings and the influence of the shielding gas.
The most common transfer modes obtained with proper parameter settings are:
- Short-circuit transfer or short arc.
- Globular transfer.
- Spray arc transfer.
Another type of transfer that has gained widespread acceptance due to its operational advantages, versatility, and application quality is pulsed arc transfer.
How can short-circuit transfer or short arc transfer be achieved?
This transfer mode is characterized by its low heat input, since the parameters used are low. It is the most widely used in MIG-MAG welding applications; for short-circuit transfer to occur, very low parameters must be used, for example: between 16 to 24 volts and an amperage range of 60 to 160 amps. These low current parameters are used for welding thin material thicknesses without causing distortion. It also allows the process to be used in different welding positions.
How can spray arc transfer be set up?
To achieve spray arc transfer, the use of a shielding gas with an argon-rich atmosphere is essential, and it must be greater than 80%. The current (amperage) and voltage parameters must average between 32 to 36 volts and an amperage range of 300 to 500 amperes. Due to the type of arc produced, it cannot be used in the vertical or overhead positions; it must only be used in the flat or horizontal position. In short, to obtain this type of transfer, the appropriate shielding gas, wire diameter, and consequently the voltage and wire feed speed variables must all be taken into account.
How can globular transfer be set up? Globular transfer is an intermediate transfer mode generated by excessive voltage, where a droplet two to three times the diameter of the wire forms at the wire tip; this produces considerable spatter, and as a result, this type of transfer mode is not widely used in welding.
