THE EFFECTS OF IRRADIATION-INDUCED SWELLING OF CONSTITUENTS ON MECHANICAL PROPERTIES OF ADVANCED SIC/SIC COMPOSITES

摘要

The effects of irradiation-induced swelling of constituents on tensile properties of advanced SiC/SiC composites were examined. After the swelling of the fiber and matrix ion-irradiated up to 1 dpa at 1000 deg C was measured, the modified four phase model was applied in order to estimate the residual stress in each constituent. The swelling mismatch was obtained between Hi-Nicaolon~(?) Type-S fiber (0.27 percent) and ICVI-matrix (0.48 percent), which increases the residual stresses according to the model. These increases of the residual stresses were roughly consistent with the tensile stress-strain behavior of the same SiC/SiC composites after neutron irradiation up to ldpa at 1000 deg C and the behavior of the misfit stress obtained by the hysteresis loop analysis methodology, which is related with the residual stress. These results suggest that irradiation-induced residual stress caused by the differential swelling of each constituent may affect the tensile properties in this irradiation condition.