Concentric ring on ring test for unirradiated and irradiated miniature SiC specimens

The flexure strength of miniature disk specimens was evaluated for both the unirradiated and irradiated CVD SiC by equibiaxial flexural test developed in this work. The results for the unirradiated specimens indicated no stress magnification at the loading point, which is often concerned in the biaxial tests for the disk specimens. Although the strength was retained after the irradiation at 1100 and 1300 °C, ∼20% of reduction was observed for the samples irradiated at 1500 °C. It is clearly seen that the smooth cleavage of large grains were frequently observed in the sample irradiated at 1500 °C comparing to specimens irradiated at lower temperatures. A substantially lower population of finer defect clusters such as loops, vacancy, and vacancy clusters may be attributed to the inhibition of the strengthening at the higher irradiation temperatures.