Aluminum Intake pipe, TIG welded with He/Ar mix

[jakeru]

Hey guys -

I am really liking mixing in a little bit of Helium for additionally concentrated arc heat, for any thick aluminum.

Here is a flange (1/4" plate of 6061-T6) fillet welded to an intake pipe (2.25"OD .065" wall 6061-T6 tubing.) I used 3/32" 4043 filler rod.

Prepped for welding:


After welding:




I didn't cut the hole in the middle of the plate until after I welded it. I did it that way to reduce distortion. But having the 1/4" plate being continuous, meant it would soak up more energy during welding and require more power for welding.

I used about 2.5 cfh Helium and about 12.5 cfh argon, with a #6 gas lens cup.

I used a 3/32" tungsten truncated point (like a crayon), 2% lanthanted. Only the very tip melted/balled.


I used 20% DCEP AC Balance (minimum on my machine.) The Helium seemed to really concentrate heat. It makes a puddle more effortlessly, and a deeper puddle, that penetrates much deeper, too. I set the pedal to give it everything it's got (200 amps) at full pedal down, but found that I didn't need to floor it. I probably used about 3/4 pedal to get the puddle going (maybe 150-160 amps?)

This is for my racecar. I'll be doing some more boost tube welding tomorrow, and hopefully wrapping up a new, experimental intake manifold for it.

Anyhow, really happy having some Helium at my disposal. It doesn't take very much to make a very noticeable difference!