Friction stir welding - GIF, video, and images

Friction stir welding GIF:

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Here's the bulkhead and nosecone of the Orion spacecraft being joined with friction stir welding:
https://diqn32j8nouaz.cloudfront.net...ding_orion.jpg


Explanation:

https://diqn32j8nouaz.cloudfront.net...planation1.jpg

https://diqn32j8nouaz.cloudfront.net...planation2.jpg


Video:

https://www.youtube.com/watch?v=aNbQH8XBgxQ

More:
https://en.wikipedia.org/wiki/Friction_stir_welding

Previously:
https://www.homemadetools.net/forum/...6268#post83362
https://www.homemadetools.net/forum/...loration-57862
https://www.homemadetools.net/forum/...tic-knot-62791

This looks very similar to Thermal Drilling for threads inprinciple.

Now, could I do something like this to weld aluminium? Seems like it might work, I could use a old carbide mill bit on my vertical mill.

Ralph

I was involved with the development of this process when I worked for Lockheed Martin at Michoud in New Orleans. We used it on the External Tank build, and later for the Orion capsule prototype.

There was just too much stress on the head to do it that way. The "button" that is used is nowhere near like an end mill. You are essentially liquefying/plasticizing the aluminum so, that it flows together.

Quote:

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Originally Posted by Ralphxyz

Now, could I do something like this to weld aluminium? Seems like it might work, I could use a old carbide mill bit on my vertical mill.

Ralph

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These might help:

NASA: Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Application

NASA: Friction Stir Welding of Additively Manufactured Aluminum Alloys

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Friction drilling. Yes, the word "friction" is becoming increasingly trendy as it applies to machining tasks, and it can reasonably be applied to the vast majority of machining processes. Still cool.

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Friction drilling, Jon says "Still cool."
Eventually yes, a bit shy of melting, the heat renders a plastic state in metal that accepts forming a different shape. As it's not quite melted, 'flow' is rather inaccurate.
Some great features, no measurable loss of material. Another with low carbon steel, there isn't work hardening. Hole matches diameter of spinning mandrel, displaced [exuded] metal remains homogeneous with parent. Thin wall tubing in GIF is ready to tap with more thread engagement, especially if a forming tap is used.

If you've watched a too-high RPM heat and dull a drill, that's the left hand version. Mandrel and material need dissimilar qualities to work as intended.
Mechanically, it is very near regular drilling. Small tip directs friction and force to a small area, and taper keeps ball rolling. A drill employs chisel tip or split point to initiate hole.

OK, looks like a good use for this is for drilling for threaded inserts, because the friction drilling action builds up the metal to be used around the insert. Making good use of the metal that would otherwise be discarded chips is interesting!

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Quote:

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Originally Posted by Jon

OK, looks like a good use for this is for drilling for threaded inserts, because the friction drilling action builds up the metal to be used around the insert. Making good use of the metal that would otherwise be discarded chips is interesting!

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I believe Jon's intended comment is, per GIF of thermal drilling, is a better solution than threaded insert. Inserts are used all the time in sheet metal but can [will] fracture under flexing action. Second clip also appears to be a forming tap vs a cutting tap. That's where forming really shines, figuratively eliminating loss of material. Great for many kinds of assembly-in-place to reduce undesirable chips in electronics or mechanical work. Only real difference is thermal drill/ thread forming is not same diameter as common tap drill procedure.

Are they intentionally friction drilling the hole to build up the hole walls, so that they can then insert a threaded insert into the hole, such that the insert will have more support on its perimeter?

Not in the GIF version, but could be done. Isn't any 'flash' remaining around the insert, a PITA to remove, doubly pointless application of thermal drilling. Rim of insert protrudes above parent metal. Thermal drilling [ferrous] in a wall thickness ~ .5 diameter creates a topside depression somewhat like a countersink; in most cases, a beneficial feature.
IMHO insert is in a standard drill hole, versus tapping a thermal drilled hole. Can't justify why the GIF shows two thermal-drilled holes. Mayhaps I'll re-visit GIF and re-evaluate.
My 'edit' button hasn't worn out yet!
Insert GIF, thermal drill has a head to roll the upper perimeter into a rim. But the flash below isn't visible, just the insert.
And still, 'edit' button hasn't worn out.

Aluminum stir welding.

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Just how is that motor working? Is the motor and wiring on the other side?

Ralph