High Temperature, Non-conductive Material

[DEngineer]

Does anyone know of any material that's not as brittle as ceramic that can withstand high temperatures and is non-conductive? I'm talking abou a max temp of 800degC of heat radiating from a hot steel coil. Components will be inside of the coil for a short period of time but trying to prepare for a system fault for where the components may sit there and cook...

 

[anorlunda]

There are many materials. Google heat shield material.

 

[Tom.G]

Asbestos is good to 1200°C and to 5000°C for a few minutes. The trouble is that it causes severe lung disease (cancer, asbestosis) if inhaled.

 

[DEngineer]

There are many materials. Google heat shield material.

You sir, are an asset to this board, and to the engineering community as a whole! Thank you for your insightful, thought provoking, life changing advice!

 

[DEngineer]

Asbestos is good to 1200°C and to 5000°C for a few minutes. The trouble is that it causes severe lung disease (cancer, asbestosis) if inhaled.

I'll look into this since I only need a small amount of it, however I'm sure our assembly team will oppose this. I'm looking for something that can take some sort of impact as it will be used on mechanical arms that close around the hot coil. They are pivoted using hydraulic cylinders, so they dock I'm sure there will be some impact / vibration. The whole point of what I'm doing is to make some type of linear position limit switch, to know when the arms have docked completely. I can't seem to the find a limit switch on the market that can withstand the temps. So since the arms are made of steel I'm thinking of using them as the switch. They close the circuit, but only when fully docked. So I need to isolate the male and female docking components as they guide each other in, then when fully docked, some type of lever or finger that can complete the circuit. So the material I am looking for will be used as a stand-off or some type of spacer between the docking components and the arms...

Thanks for the suggestion!

 

[Averagesupernova]

You sir, are an asset to this board, and to the engineering community as a whole! Thank you for your insightful, thought provoking, life changing advice!

I always thought so...

 

[DEngineer]

Asbestos is good to 1200°C and to 5000°C for a few minutes. The trouble is that it causes severe lung disease (cancer, asbestosis) if inhaled.

Your suggestion got me thinking and I found some low friction brake lining material (non asbestos) that can withstand up to 600deg C. Have a sample coming in tomorrow. If it has good machinability, then we have a winner!

 

[BFRisCool]

There does exist pure alumina paper and cloth. They are made for far higher temperatures and are flexible. You could
wrap something with this and use some metal ties to hold it together. Or, I think alumina thread or yarn may exist as well, though not sure a knot could be formed with it.

 

[johnbbahm]

Crystal aluminum oxide, might do the trick (Garnet)
It can take high temperatures, and is about the toughest material going.
Slightly less hard than diamond, but very mechanically stable.

 

[Baluncore]

Mica sheet is available in large sheets or "books". Look at how electrical bread toaster elements are made.