Ceramic
Matrix Composites
The drawback of ceramics in comparison with metals is their extremely
low fracture-toughness. It means that ceramics have a very low tolerance of
crack-like flaws.
The absence of energy-dissipating mechanisms, such as generation and
movement of dislocations in ceramics, causes ceramics to fail in a
catastrophic fashion. Improving the toughness of ceramics is the current
research goal. One of the important approaches to accomplish this goal
is via ceramic matrix composites.
Ceramic Matrix Composites (CMC) consist of fibers (carbon,
silicon carbide, alumina, etc) embedded in a ceramic matrix (carbon,
silicon carbide, silicon nitride, alumina, zirconia). They are promising
thermo-structural materials for in-service high temperature applications.
CMC maintain good mechanical performances up to 1500 °C even in oxidant
and erosive environments as it occurs in the "hot parts" of
high technology fields such as aerospace and nuclear plants.
