For the development of silicon carbide (SiC) materials for next-generation nuclear structural applications, degradation of material properties under intense neutron irradiation is a critical feasibility issue. This study evaluated the mechanical properties and microstructure of a chemical vapor infiltrated SiC matrix composite, reinforced with a multi-layer SiC/pyrolytic carbon–coated Hi-Nicalon^TM Type S SiC fiber, following neutron irradiation at 319 and 629 °C to ∼100 displacements per atom. Both the proportional limit stress and ultimate flexural strength were significantly degraded as a result of irradiation at both temperatures. After irradiation at 319 °C, the quasi-ductile fracture behavior of the nonirradiated composite became brittle, a result that was explained by a loss of functionality of the fiber/matrix interface associated with the disappearance of the interphase due to irradiation. The specimens irradiated at 629 °C showed increased apparent failure strain because the fiber/matrix interphase was weakened by irradiation-induced partial debonding.

对于开发用于下一代核结构应用的碳化硅（SiC）材料，在强中子辐照下材料性能的下降是一个关键的可行性问题。这项研究评估了用多层SiC /热解碳涂层Hi-Nicalon ^TM增强的化学气相渗透SiC基复合材料的力学性能和微观结构。S型SiC纤维，在319和629°C的中子辐照后，位移至每个原子约100个位移。由于在两个温度下的辐照，比例极限应力和极限抗弯强度均显着降低。在319°C辐照后，未辐照复合材料的准延性断裂行为变脆，其结果可以解释为纤维/基质界面功能丧失与辐照引起的相间消失有关。在629°C辐照的样品显示出明显的破坏应变，因为纤维/基体间相由于辐照引起的部分脱胶而被削弱。