THE Tungsten inert gas (TIG) PROCESS joins STEEL, magnesium and aluminum to create high-quality, precision welds. Successful TIG welding does not require control over AC balance, but these TIG WELDING SETTINGS are an exceptional feature and are commonly available on most modern welding machines. Maintaining proper AC balance was difficult in the past with limited TIG settings on older equipment. Welding aluminum must be done using alternating current. The directional flow of electrons must alternate from work to electrode and from electrode to work, cleaning the aluminum in the reverse polarity phase and penetrating the aluminum for a strong weld in the straight polarity phase. Years ago, many AC TIG welding machines and related equipment accessories did not have the luxury of adjusting AC balance. It was fixed at a 50/50 percentage. Half the cycle on DC + and half the cycle on DC -.
With such a high percentage of time on DC + (also known as reverse polarity), the inherent result was the tungsten would get very hot and even be subject to the tungsten tip melting and dropping into the weld puddle. To help mediate the lack of TIG AC balance, welders would have to take the time to purposely melt or ball the tungsten on a scrap surface before welding. This step would make the tungsten tip more hearty and better handle the excessive heat from 50% DC +. Today with the modern inverter welders, that is no longer an issue because we can lower the cycle time of DC + and eliminate the need to ball the tungsten before welding.
Modern TIG Settings Make AC Balance Easier
The newer TIG welding settings have the great luxury of being able to adjust the balance of alternating current between the time spent on DC + and DC -. Some welding equipment however measures and adjusts their balance settings in a percentage of DC + and some in a percentage of DC -.
Knowing how your particular TIG welder measures its AC balance is important to your weld and the longevity of your equipment. Too high a percentage of reverse polarity would send the majority of current from your work back up into your torch, creating large amounts of heat at your torch with the real possibility of melting your tungsten, hose, and even your entire torch head.
What are the Advantages of Adjustable AC Balance TIG Welding?
Not all Aluminum TIG welding projects are the same. For example, aerospace applications will require a different welding process compared to automotive jobs. As a result, adjusting the AC balance and other capacities with your TIG welder settings can make your welds more efficient and effective.
Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding settings provide the following control features:
- The ability to select specific AC waveform shaping including soft square, sine and triangular waves.
- Control electrode positive (EP) and electrode negative (EN) amperages independently.
- Adjustable AC output frequency for better control over bead appearance and penetration profiles.
- Extended balance control over the penetration and cleaning action portions of the cycle.
These TIG welder settings deliver the following balance benefits:
Greater or lesser amounts of electrode negative (EN) can have a variety of positive effects depending on the specifics of your application. Sustaining the EN portion of the cycle can provide:
- Greater penetration
- Increased travel speeds
- Reduced etched zone size
- Increased tungsten electrode life
- Less balling action
- Narrower weld beads
On the other hand, limiting the EN portion of the cycle delivers the following advantages:
- Less penetration
- Greater cleaning action
- Larger bead profiles
- Decreased tungsten electrode life
- Increased balling action
How Does the Weldpro Team Prepare Their TIG Welding Setup?
Weldpro measures its AC balance TIG welder settings in a percentage of DC + (reverse polarity). Keep your TIG AC balance as close to the base 30 reading as possible this will provide 30% DC+ and much more DC – which will be a good TIG welding setup that cleans the oxides from your aluminum while keeping your tungsten relatively cool.