Archive for the ‘TIG welding’ tag
How Does A Tig Welder Work?
“Heliarc” had been popular before it was given the name “TIG” or Tungsten Inert Gas. It was named Heliarc after the gas helium which was used when the process was discovered. Later, it was changed to “TIG” after it was discovered that argon worked better. Inert gas could refer to either helium or argon.
However, after several experiments more, it was again discovered that small additions of hydrogen worked well for some metals. The word “inert” became inappropriate, so it was renamed to what is now popularly called “GTAW” or Gas Tungsten Arc Welding.
Compare to other arc welding processes, TIG welding is more difficult to use though. Just like gas welding, one is required to use both hands with the torch held in one hand and the filter rod in the other. Oftentimes, a foot pedal amperage control is also used which makes it more inconvenient.
The TIG torch can either be water or air cooled. It is designed also to give shielding gas and welding current through a tungsten electrode. A ceramic nozzle leads the shielding gas to the weld puddle and internal copper parts like the collet and the body holds the electrode in place. The tungsten electrode is sharpened for applications where the arc need to be pinpointed and for very low amperage.
The heat melts the metal and makes the weld puddle comes from the arc that is created between the tungsten electrode and the work piece. Argon, helium or a mixture of both shields the arc. For some particular alloys, hydrogen is added in small percentages to improve the way the puddle flows. The arc is very smooth and quiet and clean when DC current is used. But when the TIG welding machine is set on Alternating current, it is slightly noisier but still clean and smooth.
Almost any metal can be welded by TIG. The most popular are carbon and low alloy steels like 1010 carbon and 4130 chromoly steels, Stainless steels like 304,321, and 17-7ph, inconel 718 Nickel alloy and Hastelloy X, 6061 and 5052 Aluminum alloys, az31b Magnesium alloys, Titanium alloys like 6a14v and the ones that are commercially pure, Stellite 6b and 1605 Cobalt alloys, copper alloys like Nibral bronze and pure copper and a whole lot more. Now that you know about it all, you can go out and buy a cheap plasma cutter tig arc welder and start practicing.
