GTAW - unbalanced ac and frequency

Date 04-15-2004 14:31

Who can give me an explanation or direct me to a source that can explain the effects and reasoning behind manipulating the two above variables, especially the frequency?

Thanks a lot for any help.
tjb

By Lawrence (*****)

Date 04-15-2004 14:46

Welcome to the forum TJ

You can use the search function right here in the forum to find a bunch of threads that you might find interesting. Just type in key words such as ALUMINUM GTAW, etc.

Here are a couple of links that are good also.

http://www.thefabricator.com/xp/Fabricator/Articles/Welding/Article124/Article124_p1.xml

http://www.millerwelds.com/pdf/Aluminations_Ad_Package.pdf

http://www.thefabricator.com/xp/Fabricator/Articles/Welding/Article33/Article33_p1.xml

By sparx

Date 04-15-2004 18:34

In a nutshell (taken from the Miller 200DX manual) "AC frequency controls bead width and directional control. As AC frequency decreases, weld bead/puddle gets wider. As AC frequency increases, weld bead/puddle becomes narrower and the arc becomes more focused. Travel speed can increase as AC frequency increases."
I have used this machine and can tell you, that when you adjust to a higher frequency for AC tig, this in fact does happen. It helps if you use a ceriated tungsten and sharpen to a modified point. I haven't found a tig machine that will weld in side corners/filets quite like this machine will on aluminum.
hope his helps.