Thermallt conducting compound 2

[asimpson]

I am looking for a thermally conducting compound to function at 600-800 deg. C in air.

Linking stainless steel and cast iron .

Conductivity exceeding 16 W/mK ( 110 BTU-in/hr F sq.ft.) (27 BTU/ft.hr F),

Must remain solid up to 1000 deg C.

Gap to fill 3 mm

Many thanks

 

[chicopee]

I don't know of any compound meeting your specs but about brazing or even silver soldering, altho. with the latter process I am not sure you can do that between S.S. and C.I..

 

[MortenA]

There should be com carbon material i susect? For graphite the thermal conductivity is 24 W/mK and the max service temperature is around 3500C.

Try to go spelunking at

http://www.matweb.com

 

[asimpson]

Thanks for pointers.

does graphite come in a form that could fill a gap and bond to both surfaces and conduct effectively across gap?

 

[IRstuff]

You should ask someone like:

http://www.jones-corp.com/en/series.aspx?id=817#

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

 

[25362]

Could Thermon be the answer?

http://www.thermon.com/catalog/us_pdf_files/TSP0033.pdf

 

[Ceramicguy]

At 600 or 800 degrees you are probably stuck with a dry joint design.. The fabrication and design of your joining methods will likely dominate the thermal resistance of your design. These joints in general show significant variability. Some factors that affect the thermal resistance include the hardness, finish and flatness of the faying surfaces in addition to joining pressure. The objective is to minimize the gaps that inevitably occur in real life joints.

Assuming you can solve the joint design problem and we focus strictly on potential solids meeting your thermal requirements, you might consider the following:

OFHC copper (possible interfacial corrosion products, very soft-a good thing)
graphite (you're at its upper use temperature in air, watch out for anisotropy especially in pyrolytic grades)
boron nitride(barely meets requirement,soft & machinable, at upper use temp., anisotropic, CTE mismatch)
aluminum nitride (hard-requires diamond tooling, low thermal expansion coefficient)
beryllium oxide (hard, TOXIC, low CTE)

The ceramics will be available for smaller area joints only. Minimizing the physical extent of the joint design will be desirable regardless of the material choice.

So, design your joint as small as possible, polish the faying surfaces, make sure all surfaces are flat, uniform clamping pressure, use as soft a material as possible, design for minimum warpage with temperature excursion and match thermal expansion coefficients as best you can.

Good luck,
Bruce



Bruce

http://accuratus.com