Friction stir welding
 

Read about it in my current issue of C&D. Essentially using friction, the material is melted. there is supposedly less distortion from extreme heat and you can weld dissimilar materials (steel to aluminum). It's currently being used in some auto manufacturing processes. I've never heard of it but found it very interesting. I don't see it replacing traditional welding but still cool regardless.

Per Wikipedia : http://en.wikipedia.org/wiki/Friction_stir_welding

http://www.esabna.com/us/en/educatio...ldingChart.jpg

pretty cool.. iv never heard of it either. i didnt read the article yet.. just commenting on what you wrote... the dissimilar metal thing makes no sense to me or as far as what iv been taught cause steel and aluminum touching each other causes oxidation. but the scientist prob know more then i do

Ultrasonic welding is pretty cool too. That is how a lot of plastic parts are assembled.

You are right and you'd think with the rate different metals expand/contract at it would cause it to warp.

http://upload.wikimedia.org/wikipedi...SIBOR_1500.JPG

That thing must haul ass to get hot!

i was reading about ford and their new 7000 aluminum frames will be welded like this