Fundamental thermomechanical properties of SiC-based structural ceramics subjected to high energy particle irradiations

SiC composites have a potential to be used as in-vessel structural components in a future fusion reactor concept. To investigate the fundamental process for deformation and fracture of polycrystalline ceramics, α-SiC monolith mini-specimens were irradiated with heavy ions, 180 MeV Au and 90 MeV Ni. The specimens were tested in bending after different degrees of exposure to elucidate the strength change due to artificial near-surface defects. A microindentation experiment was also carried out to characterize the irradiation damage effects resulting from near-surface defects. Moreover, an FEM analysis was carried out by taking account of the irradiation damage at near-surface region, and the result was compared with the experimental results. This paper presents the particle irradiation effect on the bending strength on the basis of both experimental and analytical results.