The effect of irradiation on the stability and properties of monolithic silicon carbide and SiCf/SiC composites up to 25 dpa

Abstract Stability and properties of monolithic and SiC f /SiC composites were measured before and after irradiation in a fast neutron spectrum up to 25 dpa between 500 and 1500°C. Dimensional changes were relatively consistent with previous investigations. Strength and modulus of SiC f /SiC composites decreased after irradiation as a result of fiber/matrix decoupling. For some composites, uniform elongation was not significantly degraded by irradiation. Thermal conductivity also decreased after irradiation at low temperatures because of the introduction of lattice defects as phonon scattering sites. The retention of properties under the severe conditions of 25 dpa and 800°C suggests that a composite tailored for neutron damage resistance can be developed.

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