Titanium TIG procedures?

[BrianPeterson]

It's been a struggle trying to find information on TIG welding Ti 6Al-4V , most welding supply shops are clueless when it comes to filler metals and procedures (including Praxxair, and Airliquide) and those that do know something are vague. I have been peicing information together peice by peice, several sources mentioned being able to TIG weld thin sheet and small diameter rod without the use of any filler metal. Is there anyone who has knowledge or experience with welding Ti?

Here is where most of the information I gathered came from http://www.timet.com/design&fabframe.html

If I get all the technical ducks lined up I have a project to build small frames using .25" Ti rod, but those ducks are looking pretty scarce at the moment.

[AAA]

TIG welding Titanium is very similar to TIGing stainless
I haven't done a lot, but here's what I was taught by a mate of mine who's done a heap.
For Ti 6Al-4V, you want to use ERTi-5ELI filler rod, as per American Welding Society Specs, but unless your building something for NASA, ERTi-1/2/4/7 or 9 filler rod will work just fine.
Most common problem with welding titanium is porosity. Make sure the area to be welded is cleaned well first with a stainless wire brush or similar to remove any oxidisation. Preferable it should also be degreased. Degreaser, cleaned off with boiling water (must be boiling so it evaporates) works fine. Same also applies to the filler rods.
To get a good quality weld with TIG, you'd normally do that anyway.
When welding make sure you use plenty of post flow, as titanium is prone to oxidization contamination as the weld pool cools.
When doing the fancy NASA stuff they have these special torches with a "trailing sheild" on them - basically this thing that sticks out out the back of the torch and floods sheilding gas over the area you just welded. With more complex shapes they stick the whole thing in an inert gas filled "tent" to prevent contamination.

That's about all I know.

Hope that hepls some.

Mike

[BrianPeterson]

Mike, thanks for the reply. The structures I will be making are definetely not going to have to be up to NASA and JPL standards! Infact, I am using Ti as a selling point, while I certainly don't want any welds to fail, they do not need to be certed but they do need to look good.

[Arbo]

Brian,

Stop by this forum and drop a note for a guy that goes by the handle "Rocky D". He works for an aerospace company in California and does alot of Ti there. He can give some pointers for sure.

http://www.hobartwelders.com/mboard/

[cope]

Another good source of information is this site:
http://www.weldreality.com/

The replies aren't as quick as on the regular chat boards, but the information is good.

[Rolly]

Brian
Thanks for the site on Titanium, I know nothing about the stuff and have a friend that wants to use it for making the reciprocating parts of a steam engine very light.
Piston, piston rod, crosshead, connecting rod.
Rolly

[Hackasaw]

welding Ti is a beautiful EASY thing.

Since argon is heavier than air...... you can weld it in a open topped box and it will definitely come out nicely sans oxidation.

Aluminum foil, as used to prevent sugaring for stainless is also very handy for welding some types of Ti pieces as well.

I find it much easier to get beautiful welds with Ti than even stainless and I've never had any filler rod. I have cut some strips of the material and used it.

I do love that it wets and flows like creamy silk and most joints can be made quite well with a minimal amount of heat and filler. Many joints will just about weld themselves if the fit up is very precise.

I've only done it four times and had instant success right off the bat. I don't know if my efforts would pass NASA inspection......... but the bend tests and a few other primitave stress tests have been very encouraging.

I think I will be doing much more titanium pieces in the near future.

I don't know what proper ti welds should look like as I don't have any books that show it but mine look like......... well........ the pieces were never welded. Totally smooth.

I hope I don't find out they should look like a stack of dimes.