Irradiation behavior of Cf/SiC composite with titanium carbide (TiC)-based interphase

Abstract Interphase failures of traditional chemical vapor infiltration (CVI) synthesized SiC composites can often be found under irradiation conditions. Exploring new interphases and the corresponding synthesized method to improve the composites performance in irradiation environments are therefore important. In this study, molten-salt method was introduced to fabricate well-distributed TiC/Ti2AlC coating on carbon fiber (Cf) fabric, and the coated Cf fabric was subsequently used to synthesize SiC composites with layered carbides interphases via PIP process. SEM and TEM datum indicate that the interphases are well integrated with the carbon fibers and matrix. Irradiation behavior of the Cf/SiC composite was then studied by a series doses of Si ion irradiation at 300 °C. SPM shows that the irradiation induced swelling of interphases and matrix increase with the increasing irradiation doses, while the carbon fibers shrink along the axial direction after the irradiation and the shrinkage of the fibers increases with the irradiation doses. TEM investigation shows that no cracking and debonding of the interphase were detected even after the highest irradiation dose (∼20 dpa). The microstructure of the interphase remains the same as the pristine sample. Above results might prove that the interphases synthesized by molten-salt method has a good resistance to irradiation induced debonding. This pioneering work shows a new approach to fabricate the interphases and explore new fiber/matrix interphase designs for fission/fusion applications.