Friction Welding

[EdK]

[Vinny]

Interesting.

[TomG]

That's the process used to attach the heads to engine valves. I tried it once and was amazed at how much horsepower it takes for even a small shaft.

Tom

[awemawson]

Also very useful for making long drills by welding an extension on.

The secret is the white heat and the final squash together of the parts as it clears oxidised material away - in fact just as you do hammer welding in a blacksmiths forge.

[4gsr]

Yeah, my brother works at a place that has several large friction/inertia welders they use to weld tool joints onto tubes for drill pipe. Some of the pipe they weld tool joints on are in the 6-3/4" to 7" OD x 4-1/2" to 5" ID. The machines have flywheels on them over 5 foot in diameter and motors running hydraulic pumps of over 200 HP!

Ken

[Dr Stan]

I've also seen clevises welded onto hydraulic rams.  Virtually 100% penetration on 2" diameters.  Cool to watch the sparks fly.