How to welding thin SS foil (0.002 )?

[leoflc]

how to welding thin SS foil (0.002")?

Hi all,

currently I'm working on a project that require to weld two thin SS foil (0.002" thick) together. and the weld needs to be vacuum tight.

What's the best way to do this?
Are there companies out there that could do this for me?

Thanks a lot!

 

[mgb_phys]

1, Depends on the shape and size but probably e-beam. It's going to be challenging to gas weld! You need to consider the shape of the join, can you make a folded join between the pieces or are you trying to just weld an overlap?

2, Yes.

 

[FredGarvin]

Did you do a search? Someone just asked this question not too terribly long ago.

 

[Q_Goest]

Did you do a search? Someone just asked this question not too terribly long ago.

Here: https://www.physicsforums.com/showthread.php?t=371495

 

[leoflc]

Thanks for the reply.
I've seen the post about Al foil, but I'm not sure if SS will be different.
We've tried TIG with folded edges, but didn't really work well..

 

[Topher925]

Does it have to be welded? There are a lot of adhesives out there for applications such as this.

 

[leoflc]

I've been using epoxy, but so far I haven't found any epoxy that can endure high temperature (300C+).

 

[FredGarvin]

I would still put money on laser or EB welding. Laser pulse and power parameters are variable. I would imagine they could be suited for such thin items. We use both of them on sheet metal. Of course, the thicknesses are drastically different.

 

[shells2bells]

This worked for me when I needed to weld two pieces of thin SS together.
I bought a spot welder on ebay and then instead of the two points coming together to "spot weld". I made two rollers of brass to attach to the ends.. One was beveled to a narrow wedge and the other was flat.

I overlapped the two pieces of SS and secured with masking tape so I could "pull" the sheets through the rollers.

Takes a little fudging with the current of the spot welder and the feed rate but it can work well.

I hope this helps.

Shell

 

[FredGarvin]

This worked for me when I needed to weld two pieces of thin SS together.
I bought a spot welder on ebay and then instead of the two points coming together to "spot weld". I made two rollers of brass to attach to the ends.. One was beveled to a narrow wedge and the other was flat.

I overlapped the two pieces of SS and secured with masking tape so I could "pull" the sheets through the rollers.

Takes a little fudging with the current of the spot welder and the feed rate but it can work well.

I hope this helps.

Shell

I have seen seam welders that work like that. I forgot all about that. That's a good idea. I wonder if the extreme thin wall would be an issue in the rollers though.

 

[shells2bells]

I first tried two beveled rollers but that was a disaster to roll through. The heat deformation was an issue when rolled too slow through the rollers and too fast you didn't get the two to melt together, but at the right speed it worked. I figured it out not even knowing about seam welders. I owned a small semiconductor equipment company for years and we always tried to think outside of the box.

Shell

 

[shells2bells]

I have seen seam welders that work like that. I forgot all about that. That's a good idea. I wonder if the extreme thin wall would be an issue in the rollers though.

I was stuck for years thinking big and small using my own internal reference on size and it always lead to bad designs or thinking something couldn't be done. .002 is just over 50um and when I built machines that would have to position to .1um over 300mm 2 thousands of an inch is very large.

The physics work the same for .002 or .2.

Shell

 

[leoflc]

Thanks everyone for the input!

Shell, I was wondering if you have some pictures of your spot welder rollers by any chance. This might be a good way for me to do it since I have a spot welder.

 

[shells2bells]

Hi leoflc,

Wish I had some pictures to send you but I don't. I did a quick drawing. Hope it helps.

Shell

 

[leoflc]

Thank you very much!

Just wondering, is there a reason to use SS pins?

 

[shells2bells]

Thank you very much!

Just wondering, is there a reason to use SS pins?

You're welcome. Brass and SS make a great bearing plus I had both laying around in the shop.

 

[Doug Huffman]

Leak proof joints in high pressure liquid systems operating at elevated temperatures are made with welded flexible omega-seals that may be as thin as 0.002 inches.

 

[leoflc]

Hi Doug,

Thanks for the info!
If possible, could you point me to an example of such weldable omega seal?
Also, do you know how are those thin seals are welded?

Thank you!

 

[Doug Huffman]

Sorry, I used them rather than installing them. The best known formed the seal between the head and vessel of the reactors that I tested.

I got a bunch of likely hits from a search.