Today we’ll be looking at the critical details behind an alloy welding process known as TIG or Tungsten Inert Gas welding of Aluminum. TIG welding is an important part of the sheet metal work, auto-body work and repair and overall application across many diverse industries. The process is often used with Hardface applications and heat treated parts, using it in your own welding project requires precision, control and a keen awareness of current and voltage levels.
With more than 820,000 TIG welding machines in use in the United States alone and over 16 billion used globally in 2020 it’s clearly an important part of the industry. In this article, we’ll answer the question: What current is used for TIG welding aluminum?
What Current is Used for TIG Welding Aluminum?
Tungsten inert gas (TIG) welding is a popular welding technique used for welding aluminum and other metals. TIG welding uses a non-consumable tungsten electrode with an inert gas to create an arc that provides the heat for the welding process.To complete the weld, a filler metal is added at the weld joint. Working with aluminum can make the TIG welding process more challenging because of the higher thermal conductivity of aluminum compared to other metals.
Aluminum also forms an oxide coating when heated, which must be removed before welding. So, when welding aluminum, it’s important to choose the right current settings.
Understanding TIG Current Settings
TIG welding current is measured in Amperes, or “amps. ” It’s important to choose the correct current setting for a given welding application, depending on the thickness of the metal and the size of the filler metal being used. Generally, thicker metals need higher amp settings and/or a larger diameter electrode to provide the heat necessary for a successful weld.For aluminum welding, a direct current electrode negative (DCEN) set up is typically used. This set up involves connecting the tungsten electrode to the negative pole of the power source.
It allows the arc to be struck more easily when starting the weld and also helps reduce the likelihood of contaminants forming during the welding process.
Common Current Settings for TIG Welding Aluminum
The recommended current settings for TIG welding aluminum depend on the type of aluminum being welded. For example:- Aluminum of up to 1/8” in thickness typically requires a current setting between 20 and 80 amps.
- For applications involving aluminum between 1/8″ and 1/4″ in thickness, a current setting of 70-140 amps is sometimes recommended.
- For aluminum of greater than 1/4″ in thickness, a current setting of 125-185 amps may be necessary.
Factors to Consider
As a general rule, current settings for TIG welding aluminum should be at the lower end of the recommended range for thin metals and at the higher end of the range for thick metals. However, it’s important to be aware that there are other factors that can influence the current setting, such as:- The type of torch being used (for example, a water-cooled torch may require a lower current setting than an air-cooled torch).
- The type of filler metal being used (for example, using a special aluminum filler metal may require a lower current setting than using a standard filler metal).
- The surface finish of the workpiece (smoother surfaces may require a lower current setting than rougher surfaces).
- The desired final appearance of the weld (heavier beads may require a higher current setting than lighter beads).