Investigation on fabrication of SiC/SiC composite as a candidate material of fuel sub-assembly

Lee, J.-K.; Naganuma, Masayuki  ; Park, J.-S.*; Koyama, Akira*

The possibility of SiC/SiC (Silicon carbide fiber reinforced Silicon carbide) composites application for fuel sub-assembly of Fast Breeder Reactor was investigated. To select a raw material of SiC/SiC composites, a few kinds of SiC nano powder was estimated by SEM observation and XRD analysis. Furthermore, SiC monolithic was sintered from them and estimated by flexural test. SiC nano-powder which showed good sinterability, it was used for fabrication of SiC/SiC composites by Hot Pressing method. From the sintering condition of 1800, 1820C temperature and 15, 20MPa pressure, SiC/SiC composite was fabricated and then estimated by tensile test. SiC/SiC composite, which made by 1820C and 20MPa condition, showed the highest mechanical strength by the monotonic tensile test. SiC/SiC composite, which made by 1800C and 15MPa condition, showed a stable fracture behavior at the monotonic and cyclic tensile test. And then, the hoop stress of ideal model of SiC/SiC composites was discussed. It was confirmed that applicability of SiC/SiC composites by Hot Pressing method for fuel sub-assembly structural material. To make it real attractive one, to maintain the reliability and safety as a high temperature structural material, the design and process study on SiC/SiC composites material will be continued.