Swelling and recovery behavior in silicon carbide irradiated at high temperature

Swelling and microstructural evolution in chemically vapor-deposited β-SiC irradiated at high temperature were studied. The 5.1 MeV Si ²⁺-ion irradiation was carried out by DuET facility, Kyoto University. The swelling value of specimen irradiated at 1873 K was 0.23 %. It shows the tendency for swelling to decrease with increasing irradiation temperature, comparing previous ion-irradiation data. No voids were detected by TEM. Recovery behavior of swelling in β-SiC irradiated at 1073 K was studied by post-irradiation annealing in vacuum up to 1473 K. Approximately linear decrease in swelling value started at around irradiation temperature. At annealing temperature of 1273 K, the swelling (0.23 %) reduced to one third of as-irradiated specimen. From microstructural observations, the recovery of swelling may attributed to the decrease in the number density of small irradiation-induced defects (black spots below d = 4 nm in most cases).