Fatigue Properties of SiC/SiC Composites Under Various Loading Modes

Because fatigue resistance is one of the most important issues for the blanket structural materials of the fusion reactor, the fatigue damage formation processes of the advanced SiC/SiC composite (Tyranno SA 3rd/CVI-SiC composite with SiC/C multilayer interphase) for fusion reactor applications were investigated. The fatigue tests of the SiC/SiC composite were successfully performed up to 10⁵ cycles with no significant technical issues by using a small specimen test technique developed under the IFMIF/EVEDA. Based on the evaluation of the modulus change during the fatigue tests, the tensile loading was clarified to be a dominant factor for the degradation of the SiC/SiC composite.