Microstructures of monolithic high purity SiC and SiC with sintering additives after neutron irradiation to a fluence of 2.0–2.5 × 10²⁴ n/m² (E > 0.1 MeV) at 333–363 K and after post-irradiation annealing up to 1673 K were observed using a transmission electron microscopy. Results showed that no black spot defects or dislocation loops in SiC grains were found after the neutron irradiation for all of the specimens owing to the moderate fluence at low irradiation temperature. Thus, it is confirmed that these specimens were swelled mostly by the formation of point defects. Black spots and small dislocation loops were discovered only after the annealing process in PureBeta-SiC and CVD-SiC, where the swelling almost diminished. Anomalous-shaped YAG grains were found in SiC ceramics containing sintering additives. These grains contained dense black spots defects and might lose crystallinity after the neutron irradiation, while these defects may annihilate by recrystallization during annealing up to 1673 K. Amorphous grain boundary phase was also presented in this ceramic, and a large part of it was crystallized through post-irradiation annealing and could affect their recovery behavior.

单片高纯度 SiC 和 SiC 与烧结添加剂在中子辐照到 2.0–2.5 × 10 ²⁴ n/m ^{2后的显微组织}（E > 0.1 MeV）在 333-363 K 和辐照后退火后高达 1673 K 使用透射电子显微镜观察。结果表明，由于低辐照温度下的能量密度适中，所有试样在中子辐照后均未发现碳化硅晶粒中的黑点缺陷或位错环。因此，可以确认这些试样主要是由于点缺陷的形成而膨胀的。仅在 PureBeta-SiC 和 CVD-SiC 的退火过程之后才发现黑点和小的位错环，其中膨胀几乎消失。在含有烧结添加剂的 SiC 陶瓷中发现了异常形状的 YAG 晶粒。这些晶粒含有致密的黑点缺陷，中子照射后可能会失去结晶性，