Composites made from SiC fibers and Corning 1723
have been studied by various groups with no report of
any deleterious reactions [12–14]. Because these composites
were made by hot pressing it is possible that the
pressure was too high for the reaction between SiC
and B2O3 to take place, hence making the release of
gas not feasible. Typical pressures for uniaxial hot pressing
are between 6.9 and 69MPa although pressures
above 100MPa have been used [20]. Moreover, subsequent
testing of the composites was carried out at temperatures
that were much lower than the softening
point of the glass, which would not allow the formation
of bubbles due to a too high viscosity.