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Electron Beam Welding - Need Help, Vendors, Etc...

Jashley73

Titanium
Joined
Jan 24, 2013
Location
Louisville, KY
My employer is quoting an assembly job that includes welding of two cylindrical parts together via Electron Beam Welding.

I had not heard of EBW before this project, and am totally confused.

We've received a quote for contract-welding services & the welding machine. Around $85 per weld (assembly), and roughly $1.6m for the equipment with an 18month ROI. Just FYI, this is for an assembly that would fit in a 10x10x10" box, and weights less that 50 lbs.

I was staggered by the costs. No way our company would sign a contract for either without competitive bids.





Does anyone have experience with any reputable companies they could recommend, either for EBW contract services, and/or machinery?





At this point we're open to consider either option. Contract welding requires more careful logistical planning & costs, and concerns about preventing rust during shipping, while leaving the parts dry & oil-free for the welding equipment. Purchasing the equipment would require someone getting certified in the welding/inspection, and learning all that comes with performing the welds in-house.




Any advice, recomendations are appreciated. Thank you.
 
It's a vacuum process, and has even been adapted for 3D printing now. But the costs you've indicated sound sort of high to me, I would definitely look for other vendors who could present a different cost structure.

Or, look at contract welding. It might be that your main customer can recommend approved EB welding vendors, I'd start there.

Let us know how this works out for you...
 
The welding is part of a larger machining & assembly project. Though I'm kicking myself now for not asking for an approved vendors' list sooner.... :willy_nilly:
 
I've only ever seen it once, it was 2 cylindrical parts that would just about fit
in a 10" box and weighed about 50lbs. Cluster gear? with a small third part with a
square hole in it?

Here is how it was dealt with where I work. Somebody in purchasing decided that
there was no difference between electrons and photons, and had it laser welded, if
I recall correctly the EBW was supposed to go an inch deep or something. Laser weld,
not so much. The weld was completely machined off in final machining.

That was a wonderful job. I think it was bid as $2000 for the first article, then $400
each for the next 40 of them. We were over $30k into it and never even got the first
article out the door.
 
Hi Jashley:
Sadly I cannot help you to find a vendor, but I can speak somewhat as to why you just got sticker shock.

As Milland points out, EBW is a process carried out under vacuum, so, of course, you have to put your assembly in a box and hold the bits in their proper relationship and program the weld path, and make sure the beam hits the proper place and etc etc.
Also, you MUST have everything exquisitely clean, not only to get a quality weld, but also to avoid contaminating the vacuum chamber.

Contrast this with laser welding:
Although you can do all of what you MUST do for EBW...you don't HAVE to, and you can still make welds that are "very good"...maybe 90% of the quality of an EBW with a much more cavalier attitude to your preparation.
So with my laser I can hold dirty parts by hand, piss a little argon stream roughly into the weld zone, point and shoot under the microscope and still do a decent job without harming the machine.

Have you looked into whether you actually need the few things an EBW can give you that a laser weld cannot?
If you can get away with laser, you will find the costs are a fraction of the EBW costs, and there are a gazillion laser welding vendors out there, many of whom can certify to pretty stringent standards.

With regard to peak performance from both processes, my understanding is that EBW can give you deeper penetration with narrower HAZ at higher speed, and if you need the best possible metallurgy in the weld, you can get there a bit more reliably, partly because of all the fussiness required in the prep work, and partly because there is no shielding gas with all its potential for contamination etc etc.

Laser welding under controlled conditions is almost as good...it would probably be worth it to you to have your company undertake a study to see if LBW is a viable alternative for your project.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
I've only ever seen it once, it was 2 cylindrical parts that would just about fit
in a 10" box and weighed about 50lbs. Cluster gear? with a small third part with a
square hole in it?

Here is how it was dealt with where I work. Somebody in purchasing decided that
there was no difference between electrons and photons, and had it laser welded, if
I recall correctly the EBW was supposed to go an inch deep or something. Laser weld,
not so much. The weld was completely machined off in final machining.

That was a wonderful job. I think it was bid as $2000 for the first article, then $400
each for the next 40 of them. We were over $30k into it and never even got the first
article out the door.


Good F'ing Grief. If you want a tragic story of EB welding gone bad:

Super Puma crash investigation Norway - YouTube

[At least, I believe this was blamed on a bad EB weld - will rewatch the video now to confirm]

[Edit: OK, this particular failure mechanism wasn't related to EB welding, although I think I remember a main gear component that was EB welded and had some root cause in a failure (but can't find a reference at the moment). On the other hand, it's a great review of a critical failure analysis on an aircraft part, so what the heck, I'll leave it here]
 
I work with a good Ebeam weld vendor and have a few other references for highly recommended EBW vendors, though they're all in California. If you want I can forward them. Most of the work I send them is prototype/small batch stuff and I'm not usually asking them to compete on cost, so I can't comment on how competitive they'll be.

Unfortunately $1.6M for an EBW machine doesn't sound unreasonable, and $85/weld actually sounds like a good price. I usually budget $100-300/weld on my parts. As a designer when I design EBW joints I think of the welds like a waterjet or milling toolpath; simple 2D projected contours are easy, but anything 3D or 4th/5th axis can get very complicated and restricts what machines can do the weld and adds cost to the fixturing and weld development.

To echo Marcus, cleanliness is super important not just to prevent weld contamination but also vacuum chamber contamination. I've had assemblies that had to be laser welded simply because parts unrelated to the weld would have outgassed excessively.

I've visited my main EBW vendor and the welding machines are like large specialty CNC mills, except with vacuum chambers for work enclosures and incredibly specialized "spindles". I believe the largest machine I saw was several million dollars. They had some 3" deep single-pass test welds in steel sitting next to it. No pre-weld chamfer.

It sounds like the weld is already designed, but it's worth noting that EBW strongly prefers welding joints autogenously. If you have an alloy that requires filler (example, 6061 aluminum) that adds a huge additional layer of pain to the weld setup and development. Maybe there's someone out there autogenously ebeam welding 6061, but my vendor has not had success with it.
 
The customer's drawing specifies EBW, as does the spec. It is not in our purview to re-engineer the assembly, simply because our/my uneducated "opinion" is that it might be a better fit for laser/TIG/MIG, etc...

Thank you to those who posted sources, I will investigate. Unfortunately I won't be able to source from the pacific coast, if there's better options in the mid-west. If only for shipping distance/costs.
 
CalG have you used Leybold and/or PTR in the past?


Thank you both.

I have not, but I drive past the facility when traveling south on 91.

I became acquainted with the operation through dealings with Leybold, prior to the PTR switch.
 
Keep an eye on the weld spec and class of weld. D17.1 for example is visual weld inspection only for class C but class B and A will need X-ray,sonic ect.

Worked at a place that bid a big job which I was already certified to weld but they didn't understand the inspection needed. They lost their butts on that job.
 
Turnworks is right. Check the standard.

In a former life I worked as a welding engineer. The costs associated with first article should include those to qualify the welding procedure. Depending on the standard this can involve examining metallurgical sections to prove penetration and mechanical tests. It may be that you can switch to laser welding which is more commonly available and often cheaper. However some materials weld better inside a vacuum. e.g. titanium is very reactive and in addition to strict cleanliness also requires a very good purge environment. Practically if laser welded (you need to argon purge both top and inside/bottom surfaces. Depending on volume may be best to find whoever did it before as they would be able to use existing qualification, if applicable.
 
like my grandfather used to say, “A penny saved is a lesson learned.” From his example I learned to negotiate up front, insist on proof of work in a product specific example and then over spec the job because no one does as good of a job as you would do yourself.
For me this works because I’m an anal, highly critical math-head and perform my own testing analysis and inspection before double checking with an engineer.
On the other hand I’m a ‘one off’ specialist on jobs that cannot be wrong. I’m sure I’d go broke running a production facility
:ill:
 
I worked on a car from March Engineering. The old joke was that the name March means "made at race car hell". In this case it was very true. In an effort to get the longest drive shafts possible to reduce the angle of the shaft at the cv joint they moved the outer cv joint inside the upright. They made long wheel drive pins and used them to bolt the cv joint outer housing to the axle. The taper roller wheel bearings were placed one on the axle and the other on the cv with 6 3/8" dia 4" long studs holding this lash up together. Put an 18" wide tire on it then run it through the corners at 200+ mph. Is it any wonder half the wheel studs would be hanging out the wheel when you pulled the tire at the first pit stop. We used EBW to weld the cv joint outer housing to the axle. It worked a treat, problem solved. You could just see a fine line at the joint. No sign of heat, just a fine line on the inside as well. It was pretty amazing stuff in 1986.
 








 
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