Electron Beam Welder

[CubMon]

I work one of these, made by Sciaky, weld in a vacuum chamber at 7 E-5 torr. Can weld 2" plate or .001" ss to itself or to the 2" plate. Marvelous NC welding machine...

At home I use a Lincoln AC/DC 225 or Snap-on C02/Ar Mig Machine (Century) - not too sophisticated to get a job done...

 

[gauthier]

Heard of them,never seen one,what do you all weld with them?

 

[CubMon]

The gun emits a stream of high intensity electrons that can be a spot or rastered into ovals, circles, trapazoids, squares, etc. and can be varied in intensity and in focus. Focused below the joint surface will penetrate and focused above will either surface melt or heat - so can be used to smooth a surface or for diffusion welding.

The work is prepared with precision fitting joints (no filler metal used) and is chemically cleaned. The assemblies are manipulated inside of the chamber similar to a milling machine so they are rotated or fed under the beam at a feed speed suitable for the material and its heatsink mass.

The welds can be confined to a needle point high intensity beam that can penetrate and leave very little weld distortion. Welding massive parts to super thin section parts is an example of the work done - such as a 2" thick bar of 304 ss welded to a .005" sheet ss foil - they become one piece of ss.

Since it is like a 'melting stylus', logos and drawings can be melted into the surface of a piece of sheet stock. It's an interesting machine to work with...

The lab uses it to weld niobiom super conducting cavities for use in the accelerator. The niobium welds must be super pure on a molecular level with absolutely no contaminates. That's the reason for the high vacuum in the chamber - 7 E-5 torr - but it can go as low as 3 E-7 torr. That is low enough that even nitrogen is condensed in the cryo pump.

Bill C.

 

[BlacknTan]

We had one where I spent most of my career. Truly an amazing machine, and capable of gorgeous work led by the right hands!
Oddly enough, it was part of the Toolroom, and run by a toolmaker instead of being part of the Weld Dept...

Don't read anything into that... just a quirk in a quirky place. Not a comment on anything other than that!

 

[gauthier]

Interesting and thanks for the info,[no wonder I never been around it,never even heard of niobiom]

Brings up welder certification,[some people think that a guy who is certified,,or says he is,,],is a welder of all magnatudes,,,been trying to tell people for years that certified welder might just mean he MAY be able to weld flat with a mig,,many processes,many differerant weld joints,and positions,,

Not trying to alter your subject,just saying something that popped in my head.

 

[CubMon]

Last count, there were four niobium welders in the world, and I are one...!

The main drawback to these machines is gun-arc. That's when a small particle of material shorts the filament and the gun releases all of it's energy in a microsecond through the weld joint and melts a hole - sometimes all the way to the floor of the chamber. It leaves a divot and because the gun is out of focus due to distance, it doesn't burn a hole through the 1" thick stainless steel vacuum chamber. That would suck!

We must certify welds now and then for pressure (vacuum) vessels and they usually basically consist of pull tests. The strength of the weld is usually greater than the parent material.

I used to stick weld years ago and was certified by Coast Guard standards - so that I could stand on my head down in the fore-peak bilge of a boat and weld bulkheads in. I still have the headache! Yes, certifications are usually not a total coverage of different materials and welding equipment. They are very specific.

Bill C.

 

[gauthier]

Well,sounds like you are a very expienced man,who is into the latest stuff,you could without a doubt teach us all a thing or to,,[course electron beam probably ain't close to the latest,been hearing about it for years,rare would be a better word.]

 

[CubMon]

I hope I can help out here some but I'm sure learning a bunch just searchin' and readin'. Great forum! Miles and miles of experience and good humored advice.

Bill C.

 

[yomax4]

Very Cool Stuff..Although a different Animal, I sell Plasma Welding Equipment. A little less Tech but useable for everyday without a Clean Room.. I am very interested in the Electron Beam stuff or similar. Lets everyone know where we are going in the Welding World. From Stick to Plasma to Electron Welding, Major differences here. :thumbsup:

 

[CubMon]

The really wild and hitec stuff is manufacturing parts with a deposition system. Complex parts that cannot be machined can be made. Engine blocks with oil galleries and cooling circuits made into the parts...Stereo Lithography with metal.