Concerning the open porosity, SiC particle size does not seem
to influence this property significantly, as open pores are eliminated
for all compositions at 1190 ◦C, except for the composition
with the smallest SiC particle size (d50 = 0.5m), which shows
a pronounced increase in open porosity at temperatures above
1190 ◦C. This behaviour, typically found in glass foams,20,21
indicates that under these conditions the porous texture of these
pieces is made up of a connected pore network that is open to
the outside, as a result of the high pore coalescence and of the
more effective oxidation of SiC, generating higher gas pressure
inside the bubbles facilitating the formation of cell windows.