Joining aluminum to aluminum mesh

Hi,

I'm wondering what the best way to do this is (I'm not a metal worker). I have a spherical aluminum mesh, 3" in diameter, sliced in half. I want to join the circular edge of one of these halves to a piece of aluminum foil. In addition, the resulting merged unit must be thermally stable, as it will be exposed to (relatively low) heat when used (ie., no glues or adhesives). The joining itself will not be under extreme stress or weight in use, so one or 2 joining spots are enough, enough to keep it tacked in place.

Is there a welding (or other) process that can accomplish this?

Thank you

Reply to
Dimi Shahbaz
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3M makes an epoxy that is good to 500F
Reply to
Tom Gardner

There a number of ways. If your materials have sufficient thickness they can be TIG welded. Thin materials can be furnace brazed. For low temperature applications there are solders for Aluminum.

How about giving me some numbers, dimensions, and the quantity, is this a thoudsand or a one off? Dave

Reply to
Mechanical Magic

As far as thickness, I think that's a problem. I want to use regular commercial aluminum foil, so 0.2 mm thickness. The diameter of the mesh will be 3", the foil will extend past that a few inches. If it can be made in the thousands, that would be ideal, and preferably at a low cost. Non-corrosive metals other than aluminum would be fine as well, if the process is easier.

Thanks again

Reply to
Dimi Shahbaz

RTV silicone should work. There are easily available formulations good up to 500F. The common hardware store stuff is usable to 350F. More exotic flavors go higher.

Some sort of air powered dispenser and perhaps some fixturing would be helpful if you're making thousands.

Reply to
Ned Simmons

OK, if I have this right, you have a hemisphere of thin aluminum mesh. You also have a cylinder of foil (.2mm) that you want to join to the cut edge of the hemi. You are going to heat this above 500 f, ruling out epoxies.

?? How hot are you going to go?

You need to make a few thousand. Strength is not an issue.

The following are some thoughts: Spot welding Rivets Aluminum Solder (depends on question above) Electron Beam welding

If this assembly looks like a cup in a tube, then crimping.

My worry is strength, and the direction of forces, any further info might help. Dave

Reply to
Mechanical Magic

If we're voting here, I generally agree with Ned. Any kind of metal joining (soldering, brazing, etc.) is extremely difficult with aluminum foil, although I have soldered it with success, after many attempts. The point contact, however, would make that a problem.

Epoxies and silicone adhesives can take a fair amount of heat, as others have reported. Getting a strong bond to aluminum foil is, again, a problem. Unless you use special techniques to prepare the aluminum, you will be bonding to the surface layer of aluminum oxide, not the aluminum itself.

That's generally a weak bond. But you can't apply much load to aluminum foil anyway, so just gluing it may work. Although I favor epoxies for most bonding, and silicone is not a great adhesive, the silicone will be more compliant and it may do a better job in this case.

If it were me I'd try the silicone adhesive as a test and see if it's sufficient. If it is, it's probably the easiest and cheapest to apply.

-- Ed Huntress

Reply to
Ed Huntress

I would seriously consider using slightly thicker aluminum foil. Then form and pierce the foil to form the mesh part. If you are making thousands it would be much quicker than using any sort of adhesive , welding, or soldering.

Dan

Reply to
dcaster

Shaped meshwork is common in vacuum tubes and electron microscopes... the usual procedure is to form the mesh, then electroplate it to fix all the wire-crossing points. Aluminum isn't the preferred material, of course, but some alloys might accept plating adequately.

Reply to
whit3rd

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