Dear all,

as a part of my scientific work, I have to try to etch Al2O3
substrates by wet-etching methods.

First I tried to etch the Rubalit 708 96% (supplier CeramTec)
substrate with 85% -solution of Phosphoric acid and in a mixture of
water, phosphoric acid and nitric acid It etched slowly with the
etch-rate of approximately 37 nm/min.

After this short success, I changed to the Rubalit 710 99,6%
substrates and tried the same etching method, but this time nothing
happened even after the temperature of the solution had been raised up
to 85 C.

The question is, are there any differences in the structures of
Rubalit 708 and Rubalit 710 or any significant differences in a
production process which could influence the solubility of these
materials?

Does anybody know or have any experience in the chemistry of ceramics?

Many thanks in advance!

Regards,

Denis Petrov