Hi All,
Perhaps somebody have  solutions for a glue problem.
We are cladding a ceramic component in a Teflon housing to protect it
from harsh environments. We have to join the teflon acoustically to the
ceramic. This is done by etching the teflon and glueing to it.  At present
a terrible concoction of chemicals is used for etching, Na metal  in
ammonia. This roughens the surface of the teflon and apparently
chemically modifies it, in 6 to 12 hrs,  to a carbonaceous residue?. The
result, glue strength, is  variable .
 My questions are:
1. How to non-destructively evaluate the suitability of the etched parts
before glueing them?,
2. What are the physical/chemical details of the etching process?,
3. Any other processes like reactive ion etching possible and/or better
and where to get it done?
4. Can one get an alternative, highly chemical resistant material, such as
perhaps poly-imides in a form suitable  to hermitically clad a 3-D shape
of say 5 cubic centimetres?
5. In 4 above, a low impedance acoustic junction is still needed. In this
regard one could perhaps think about the  processes  used to prepare
the surface of, for example, poly-imide for Cu coating. How is that
done?
Thank you,
Frik Koch