I think this is what you re saying using nano silver http://www.nature.com/srep/2013/131029/srep03066/full/srep03066.html?message-global=remove&WT.ec_id=SREP-639-20131101
Airtight metallic sealing at room temperature under small mechanical pressure On Thu, Jan 1, 2015 at 11:50 PM, Bob Higgins <rj.bob.higg...@gmail.com> wrote: > Ceramics, including aluminas, that are proton conductors are intentionally > doped in the grains with metals designed to provide a chemical transport of > hydrogen ions through the body, primarily at the grain boundaries (as I > understand it). The CoorsTek AD-998 alumina is not designed for proton > transport, but there may be some small residual rate. A leak through pores > would be a gross leak for hydrogen, particularly if the pressure really > turns out to approach 100 bar. > > He leak testing is a standard way for evaluation of hermeticity, but the > test apparatus is usually fairly specific to the package being tested. In > this case, the reaction tube is fairly large and may need a custom system > designed to do He leak testing. > > Bob > > On Thu, Jan 1, 2015 at 7:27 PM, Bob Cook <frobertc...@hotmail.com> wrote: > >> I would say the surrounding alumina is the seal that is important, and >> I do not think it is an hermetic seal. Its porosity allows some leakage, >> particularly at the temperatures of 1000 degrees C. Thermal stresses in >> non-ductile materials are bad when it comes to hermetic sealing. Glass >> which flows is somewhat better. If one wants real hermetic sealing, he >> should test it at temperature with He for leakage. >> >> Bob >> >
