Please help me out here. My boss just came to me and asked if titanium was weldable. I said "yes, but if you are thinking about quoting something, we are currently not equiped or capable". He, of course, is a Missouri type (Show me!).
So, all you smart and experienced welder types (I'm a quality type), please give me the Reader's Digest version of a titanium welding process.
I do remember a previous company I worked for doing some R&D on this process. They tried welding in a sealed booth, completely (or so they tried) evacuated of any atmosphere, and under a 100% argon blanket. They were not successful (something about severe oxidation at elevated temperatures?). This is pushing some 20 years ago, so I'm not current with any new developments in this area.
Thanks for your help.
Hey Ron!
Don't be discouraged. There are many titanium welding applications that can be done without a box or bubble. The truth is that most of those dry boxes are collecting dust in shop corners across the fruited plain.
Rather than blather on and on, let me suggest that you run a word search on this forum with the keyword titanium. Be sure to set the time limit to 999 days and the number of posts to 100 so you can get the maximum amount of data, there are many extended discussions on the subject of titanium welding, especially involving the gtaw process.
Also, Tell us about the project your boss has in mind. Things like type of weld, parent material, thickness, size of production run, the process you have in mind and any code you must adhere to. The more data you can provide the more specific your answers will be.
Here are a few links that will help you get started
http://www.timet.com/fab-p27.htm The basics from a trustworthy source
http://www2.thefabricator.com/Articles/Welding_Exclusive.cfm?ID=878 The fabricator uses down to earth terms to describe weld protection and the dreaded "Alpha Case"
Besides following Lawrence's advice, which I think is excellent, you can get in touch with the titanium great specialists: Titanium Metals Corp. at www.timet.com
Giovanni S. Crisi
Sao Paulo - Brazil
Have you tried the recommended practices for GTAW of titanium piping and tubing? Order # D10.6/D10.6M:2000 $33.00 for AWS members.
I have this manual and used it in ASME applications.
Hey Bama
Is there any usable data in that $33 AWS spec. that you can't get for free elsewhere?
D17.1 has all the titanium aerospace requirements for qualification but really speaks very little to technique, surface prep or process control.
EWI and TWI used to have lots of excellent articles available but now they require membership, but again, that data is available elsewhere for free.
I am not sure what info you have found but i have the D10.6-91 version right here. As far as techiques go it recommends high freq. start, run-off tabs, key-hole technique on root pass, post-flow gas, etc, etc.
Surface prep. dilute solution of sodium hydroxide ( alkaline wash) or acetone, alchol, methyl ethyl ketone (solvent wash) or abrasive cleaning if care is taken not to overheat the metal. I am not sure if this is the answers you are looking for , if so find this manual or ask me .
This might help also as an intro.
http://www.twi.co.uk/j32k/protected/band_3/jk24.html
TWI also do a very useful pdf file referred to in this link
http://www.twi.co.uk/j32k/unprotected/band_1/bpweldtis01.html
but you need to be a registered member to access it
but registration seems to be automatic and free of charge - try it!
Cheers
Andy
Titanium is quite weldable with the right preparations. You will need special purge fittings know as "trailers" which keep the heat affected zone covered in an Argon blanket.
You can make your own trailer as all it is is a gas diffuser. The ones I used were 14 to 16 inches long, maybe 2" wide and 3/4" deep. Picture a rectangular box with those dimensions made of thin stainless steel...on one of the 2" by 14" sides there are gazillion holes (1/32" dia) spaced about as close together like a salt shaker face. Inside the box , is filled with steel wool. On one of the smaller ends is a female hose coupling to accept an argon hose. One or two (depending on the type joint) was placed on the back side of the joint to be welded.
You will need a smaller version of the same thing modified to fit on to the cup of your tig torch. You will need a water cooled torch as you'll need plenty of amps plus your welding supply should have a pulse feature.
The Titanium I had the experience welding was 1/8" thick and varied between butt joints and fillet joints. The trailers were hooked up to their own separate argon regulators and cranked up to 45-55 CFH. The way I was shown whether the welds were acceptable (having no technical knowledge then or now) was by visual examination of the welds and HAZ. A very light straw colour on the HAZ was alright but if it was blue coloured forget, cut it out and reweld. The amps were set between 180 and 220 DC-SP.I was amazed at the amperage setting compared to the thickness of the material and it was similar as welding aluminum in the way the puddle accepted the filler wire.
While argon is inert, it displaces oxygen and will settle in your lungs so after a shift of straight out Titanium welding , you should lie down with your feet above your chest to let the air push out the argon which you have inadvertently ingested.
Hope that helps.
Thanks to all of you. Your feedback has been very informative and helpfull. I can now approach my boss and actually sound like I really know something.
Ray
use tig cold wire feeding system.
this will decrease the heat input due to the fact that the filler
is always inside the weld pool
gives you tig quality and mig speed
look at www.tigerprocess.de
franck
Greetings,
I weld Titanium for the aerospace and medical industries. Check out my web site www.caweldtech.com I have a picture of a vacuum purged glove box and a detailed explanation of the process. I have found the use of this laboratory equipment to be the most cost effective way to produce consistent welds for mission critical applications.
Dave
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