Friction Stir Welding

Thanks for the question -- I've never used it and would not have looked it up, were it not for your post: interesting process. The closest I've come is when drilling into a piece of steel, and rushing things, and the bit welds to the steel.

Usually done on a lathe or milling machine. The surfaces have to be clean and oil free. A little lye between the surfaces seems to help with steel. Lye and rust in combination burns hot enough to weld railway sections together. I have a formula for that in a book. I tried to join brass by friction welding but the brass I was using tended to flake rather than melt. The smallest piece of steel I tried was a 3/4 inch stud 4" long. Plug your ears because it's going to scream. Make a flat contact at high speed, apply a little pressure to build heat. Then when the stud is getting white hot stop the machine and maximize the pressure. Let it sit under pressure and cool. I don't recommend doing this as it can heat your lathe or mill head up. Friction butt welds like this work sometimes. Its not as reliable as other methods of welding because it introduces malleable twists in the contact which weaken the weld.

Hi sabo:

I think the original poster was talking about a different (though related) process that was developed at Cambridge. Heres' a link. In this process, the pieces to be welded are held stationary like they would be for ordinary welding processes, and the probe advances through the weld zone, stirring things up and creating heat. Looks like a pretty neat method.

There is a belgian company, SAPA RC Profiles, Member of SAPA Group. This company is located in MONS ( Belgium )- and has started a new equipment very recently inaugurated , able to use friction stir welding for ALuminium profiles.

Y you want to learn more, contact Dr. Jacques DEQUENNE, E-Mail : jacques.dequenne@dequachim.be

One of the new very light jet companies, Eclipse 500, uses it for assembly of thin guage aluminum.

I have a friend that was the director of engineering at a company that used. Imagine a big TIG welder combined with a drill....it presses hard on the metal, spins and fires current through it. The current melts the metal, the spinning forces the metals to mix (essential if you want to weld un-like metals).

In a nutshell, friction-stir welding is the only way I know of to weld non-like metals....anything more than that, I'd like to heard about.

Cheers.

Contact Damien Kirkpatrick at The Welding Institute, TWI, Cambridgshire, England www.twi.co.uk They are an international centre of excellence for FSW.

This is the viagra of welding!!!!!!!

Try an Areospace company which makes turbine engines or a turbocharger manufacturer. Try going through the nearest State University in the vicinity of one of these companies. (ASU for instance)

Sorry I don' t know any smaller companies that use it.

Eclipse Aviation completed an extensive development program to get FSW certified for its VLJ, now in production and delivery. The following statement is from a white paper that can be downloaded from Eclipse's website:

"Friction Stir Welding (FSW) has been used to attach most external skins to their stringers and frames, replacing over 7,000 rivets in the aircraft. The FSW gantries utilize CNC programming for highly accurate joints to improve the overall reliability of the structure and to facilitate interchangeability of replacement assemblies."

You might try contacting someone from Eclipse if you want detailed information. In aviation, they are probably the most experienced with FSW.

A japanese company uses it for joining thick aluminum floor sections for the high speed train fabrication. I don't belive current is used in this process just super stout fixturing to hold the pieces and to send the spinning bit through the weld seam. From what Ive read it can only be done in the shop and the equipment is super expensive. I beleive ESAB is one of the co. that is working on the development.

Thanks

Boeing has used fsw for years on the Delta launch vehicles. The LOX tank, Fuel tank and interstage body on the Delta II were all friction stir welded from 3 sections of aluminum for each assembly.

THANKYOU FOR ALL THE REPLIES.

I WILL LOOK DEEPER INTO THIS PROCESS.

Yes I have used friction stir welding in many application for the last 3 or 4 years. Our work has been in the semiconductor equipment manufacturing industry. We have used friction stir welding for fabricating large vacuum chambers, milled groove heaters, and others.