Aluminum TIG Welding 2

[sreid]

Gentlemen,

Where I work we have a mechanical designer who often makes bold assertions to support his position that I believe are often specious. Having said that:

A weldment had to be made from 304 SS instead of Aluminum because it would be very difficult to weld Aluminum. The weldment is a 1/16 inch thick plate with a 2 inch diameter, 1/16 inch wall thickness tube welded to it.

I believe that with properly sized modern welding equipment, 6061-T6 Al can be welded just as easily as 304 SS.

Your comments and opinions please.

 

[mechengdude]

Both can be welded although I'm not sure I'd have alot of confidence in a 6061-T6 weld joint as the welding process would bring the aluminum back to it's annealed condition resulting in little to no strength at the joint.

Probably need more detail design specifics to properly address the issue. Good luck.

 

[sreid]

It's a totally unstressed part. Vacuum air flows through the tube into a cutting chamber for lathing plastics..

 

[ornerynorsk]

This is not a big deal for a good tig welder. We have guys that routinely weld beer can thickness material.

 

[drawoh]

sreid,

Aluminium 1/16" probably is 14 gauge, .064" thick.

The welders I have talked to want to see aluminium at least .102" thick if you expect them to do a good job. I do not know about the stainless steel.

Anything can be done if you are willing to search for the guy who can do it, and if you are willing to pay for it.

JHG

 

[dvd]

http://www.lincolnelectric.com/knowledge/articles/content/comistakes.asp

 

[Compositepro]

Great references, DVD!

 

[IFRs]

I have welded miles of 0.050" aluminum tubing and miles of 0.040" aluminum sheet. MIG though - not TIG. Go for it unless your welders just can't do it.

 

[tbuelna]

sreid,

The aluminum flange/tube parts can definitely be TIG fusion welded with either an inside fillet or external corner butt joint. But sadly for you, your "specious" coworker is likely correct. The 304 cres parts would be easier to weld than the 6061 alum pieces, especially with those thin sections. This is mostly due to the fact that controlling the heat at the weld zone in the 304 cres parts is much easier due to their much lower thermal conductivity/heat dissipation than the aluminum parts.

Another thing to consider is that the aluminum parts would probably also suffer from greater distortions in the finished weldment with those thin sections. So if weight and cost are not issues, the 304 cres is probably a better choice for this particular situation.

Good luck.
Terry

 

[btrueblood]

Agree, nice link dvd.

Tig welding coke cans:

http://www.youtube.com/watch?v=2X6RgJoXfZQ

One way to limit heat distortion in the flat sheet would be to roll form a lip on the edge of the hole, the weld then being made on the end faces of the tube and lip...but that is tough to do without a punch tool, and tougher yet in aged 6061 (but if you annealed to to the O or T4 condition...?)

 

[IFRs]

MIG minimizes heat input. The SS will warp up also but the aluminum will be easier to beat back down.

 

[EspElement]

Well, with aluminum having a lower melting point just in general would make it harder to weld.. I have a machine shop do my aluminum welding cause our guys cant do it.. Their welds seem to come back around 1/4" (have called out smaller and it seems they have trouble doing it).. i never requested it to be processed by TIGW, however before now i didnt think it was all that easy to do.

Im guessing you are concerned with corrosion wanting to use alum or stainless.. are you concerned about weight?

 

[sreid]

No, this problem is about politics. The reasons given by this individual range from the possible to "Did you think I just fell off the Turnip Truck?" But most of the other managers are clueless [or are on the glide path to retirement]. Or have a Go Along and Get Along attitude.

Thanks to all who have replied. I'm going to put this in the "Possible but I Smell Livstock" category for future use.

 

[unclesyd]

If you have any quantity you can always look around for some Micro-Tig equipment.