refractory ceramics bonding? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 08:06:31 am
content: Lets say you have some ceramic objects you want to unify. An alumina tube and an alumina substrate for instance.It is possible to make the whole thing from alumina, but how about a way to just join them for prototyping purposes? Like if I wanna lay some tubes on a alumina or nitride plate, bond them to it, and then further do things to it that involve high temperatures.I know there is furnace cement. But are there other, perhaps more expenisve and uneconomical for home construction tasks types of bonding agents for this purpose?It's hard to find information for these kinds of small jobs that might be physics prototypes, all the results come up with objects that are brick sized. I mean like say bonding a resistor sized 1/8 inch ceramic tube onto a ceramic substrate that might be 2x2 inches. Or like attaching a bushing that can be used as a anchor for a tiny rod or somethingAnd it would need to be able to take like 1000c afterwards for adding thick film, silver, etc.. .and not fall apart .. just basic 3d objectspreferably RF transparentI feel like I am seeing the 'cheap construction adhesive' side of things, but not the high end 3m epoxy side of thingsSome kind of clay..? can it be used like glue?

author: Nominal Animal
author_rank: Super Contributor
timestamp: May 25, 2025, 09:07:09 am
content: Ceramabond 503?

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 09:07:50 am
content: perfect

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 09:15:06 am
content: They have alot of options there. 503 has PSI listed for tensile.The other ones only have torque strength. Are they related parameters?Becuase other ones have as high as 73 foot pound torque strength, but unlisted tensile strengthThe only downside is that it looks like its not for binding macor, you need a different glue for that (compatability table). But I never even saw that before, just something that was in the back of my headaluminum nitride too. I think I have one tiny plate.But at least they cover all the options.Is this kind of like considered the high end of these types of glues?For comparison epoxies are 4500 psi or so for the good onesThis looks like similar to working with frit, you need to select the CTEthe 571 can do copper to ceramic too. That's interesting. You could put studs on ceramic PCB for mounting with screws using that. Bus bars on ceramic too. It should work OK if you make a fixture to hold it in while tightening with some featuresI wonder how it compares to the glass/silver on ceramic, if you instead.. just bonded a sheet of copper to it with high temp adhesive, to make a etchable ceramic PCB instead of a thick film one. It might have similar properties but not require a stencil. Though, given difficulties I had with making PCBs like that, I don't think I will try.. the silver seems like it works well.

author: Nominal Animal
author_rank: Super Contributor
timestamp: May 25, 2025, 10:00:29 am
content: I'm only a hobbyist! I know ofAremcoandResbondhigh-temperature ceramic adhesives, but in theory only, having looked at (but not used) stuff like thermocouple and RTD adhesives for a fusor project (flask body temperature measurement, not within vacuum), and ceramic adhesives like Resbond 920 for my own DIY electric furnace stuff –– the heating wire tends to break around tight corners so judicious dabs of adhesive to keep it well in place while still allowing the wire to expand and contract sounds like a good idea to me –– but haven't actually used them yet.It was you mentioningalumina/aluminium oxide –– these usually are based on it, or magnesium oxide –– that triggered a faint memory, causing me to re-check and post just a quick suggestion. Apologies if I sounded like I had actual experience!

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 04:18:36 pm
content: it looks like they might interact with scientists and people that use advanced technology more then like potters so its probobly OKif its a product for scientists it ends up doing weird stuff

author: Nominal Animal
author_rank: Super Contributor
timestamp: May 26, 2025, 12:19:58 am
content: Yep, those two companies are pretty high-tech/science-oriented.I do know that for alumina ceramics, the alumina adhesives will work well. Depending on the product, the temperature range, shear strength (forces parallel to the joint plane), and tensile strength (forces perpendicular to the joint plane) do vary somewhat; and that finding out theexactapplication method is quite important. If at all possible, I would test. They are actual adhesives, not just like refractory cement.Right now, I don't even have the electric kiln yet. 🙁 Would be nice to cast my own aluminium heatsink blanks for SBCs, they need protuberances to reach the SoC. Typical junk alu is so dirty welding is not really an option.