Non-Metallic Arbour Press

This sounds like a very specialized (custom) type of press for an experiment. In my first attempt, I would use ceramic pieces (bricks) to an existing arbor press near the coil. Many ceramics will endure very high pressures without breaking.

It certainly is specialised (like most stuff we do). Typical arbour presses don't give you much room for adding ceramics etc. From my searches so far, you can get a press with a deep throat or a tall throat but not both. We would need to get a 100mm diameter induction coil into the press with enough clearance to avoid the magnetic flux heating the press. The non-metallic press question was a forlorn hope that there might be something out there but I don't think it exists.

The experiment is just to establish some parameters for a process which will eventually happen inside a vacuum chamber.

The heating will happen inside the coil. Outside of the coil, the heating effect will be minimal because of field cancellations. The critical exception will be near-field effects at the ends of the coil. Strategically placed ceramics transferring arbor pressure at these locations should allow valid experiment performance.

I have asked the company who supplied our inductive heating machine if they can say how far the flux extends beyond the ends of the coil. Waiting for a reply.

Since your inductive coil will be under the item to be heated and pressed, don't forget to ask how much weight (mass + press force) the coil assembly can handle.

The coil is cylindrical so everything will pass through the centre.

This image was posted on Wikipedia.

Very little heat is produced outside of the coil. Any non-conductive shims can transfer the arbor press force. Just make sure those shims can withstand the unstated pressure and temperature.

you did not mention how much pressure you need to apply.

Many years ago I made a press from a hand operated hydraulic jack and a metal backed hard wood plunger into a hardwood form. It was a12 ton jack and never broke the wood. I did have a metal plate on the back of the form, which was 7 inches tall. I had an angle iron frame that was a two foot square. The form bolted up into it. This would have been safe for your inductor size.

We may have to do something similar, We do have a 10 ton garage style hydraulic press which would be complete overkill for this experiment but could be used.

To save space you could incorporate your induction coil onto the surface of a ceramic plate. This would give you a direct heat source where you need it and reduce the amount of space needed.
What sort of pressure will you be using? As you are referring to wafer bonding I presume that the parts concerned will be small?
You could use a wooden press then you have no negative effects from a metal press whatsoever.
Wooden presses are used in cheese processing and wine making with a mechanical pressure function.
As you stated this is an experimental set-up so making a small wooden press should not be too hard or look an the internet to see what is available which you could adapt.
When I worked for Mercedes Benz Technology Group I dealt with their Ceramics Dept. in Dresden on a Ceramic part used in a Hydrogen Gas Sensor project.
You could try contacting this guy, he might be able to help you.

Simon Andrews

Executive Director
Fraunhofer UK Research Ltd
Technology and Innovation Centre
99 George Street
Glasgow G1 1RD
United Kingdom
Telefon +44 141 548 4667

• E-Mail senden
• www.fraunhofer.co.uk

Thanks for the suggestions. We have an existing high frequency induction coil set-up so I can't change that. The idea of using a wooden press is one I hadn't thought of. A quick Google has found a Dutch cheese press which could be suitable.

Hi Nigh, there you go.. sometimes the simplest ideas are the best.
And you could always try your hand at making homemade cheese, make a change to Cheddar !!

Lots of interesting ideas! Would a "reverse Faraday Cage" work to keep stray flux lines inside the coil be of any help?

That would possibly work. We're planning to see how close we can bring a metallic strip to our existing coil to establish some parameters.

..."The Coors Ceramics Company developed these ceramic hammers to show off the quality and strength of their ceramics. Although these hammers were never sold to customers, top salesmen would bring the hammers to show important clients. This was an effective method as clients were always impressed when the hammer did not break, even when pounding in a nail.

A member of the team that invented this hammer said:

“I tested it on everything that [I] could think of and found it to never break.” "...

https://www.coorstek.com/en/materials/zirconia/

Maybe a dental supply house might deal in these type ceramics...

https://keatingdentallab.com/videos/zirconia-crown-flexural-strength-test-kdz-bruxer-hammer-test/

blah blah blah.....

We buy a lot of ceramic parts so getting those materials is not a problem. I was lucky enough a few years back to participate in a staff sale by one of our ceramic suppliers & was able to buy some excellent ceramic chef's knives for my 2 daughters.