What can weld Titainium, A mig, A tig? I need to know for an upcoming project.

 

Titanium can be Tig welded with caution, Titanium and titanium alloys become very reactive above temps of 550c, sheilding gas Argon and helium only and sometimes a mixture of the two. large cups need to be used, Molten titanium cannot come in contack with air and will react if it does.

Argo and Helium sheilding gas needs to be UHP

Most Titanium casting and welding that ive seen has all been done in an evacuated helium filled enviroment. ( Glove Boxes )

Good Titanium Link

Be carefull.

Rick D

 

Beat me to it Rick. The shop I worked in had an emergency titanium repair job brought in. We cleaned up a sandblast box and sealed it. Installed the tig torch and weld rods plus the parts. The the box was purged a number of times. A heavy flow of argon plus the flow thru the torch was used. The welds looked very good. It was very expensive as a lot of gas was used and a lot of prep time by several people so the labor cost was very high. It welds a lot like stainless steel. Not hard just try not to get too much heat in it and keep the electrode perfect. If you "dip it" you need to change it and grind out the mess. I don't know if these parts ever passed some weld inspection or not. It was all pretty hush hush. Somebody made a big mistake apparently and needed it fixed quietly and fast, cost no object.

 

Depending on thicknesses, Tig for thin, especially automated Tig. Thin stuff <2.5mm square groove butt joints no filler metal, thicker stuff use a groove and filler metal.
>3.18mm GMAW-Pulsed works good. AWS A5.16 lists 13 filler metals.

Can't stress cleanliness of base metal, filler metal, critical procedures require cleaning of filler metal (remove lubs used in manufacture) and base metal immediately before use.

Like "bentwings and Rick D" said shielding gases critical, Ar (cheaper), He (best for out of position, and thick stuff) or combo 75% Ar- 25% He, (Ar arc stability, He penetration).
He results in higher arc voltage, Ar better on thin stuff, can alter arc length without increase in heat input. Weld metal

Welding outside controlled atmosphere, joints must be designed so that both the top and underside can be shielded.

Alpha-beta phase harder to weld vs alpha-beta or metastable beta alloys.

ASTM Handbook Vol. 6 got me through college now time for another pop, I just love my day off.