Effect of Si Ion Irradiation on SIC/SICF Composites

Abstract

SiC/SiC_f composites have recently been considered as an innovative candidate cladding material in fission reactor because of its intrinsic low activation, chemical inertness and superior high temperature mechanical properties. At the present time, however, very few data are available considering the performance of SiC/SiC_f composites made in China after irradiation. In this work, SiC/SiC_f composites were irradiated at 300℃by 4.5 MeV Si²⁺ ions with fluences ranging from 1.4×10¹⁶cm^-2 to 2.8×10¹⁷ cm^-2 , which correspond to peak damage values of 5 displacement per atom (dpa) to 100 dpa. After irradiation, both SiC fiber and matrix have been studied via the combination of in-situ scanning imaging nano-indentation, Raman spectrum and scanning electron microscope (SEM). Nanoindentation results show that after irradiation, the fiber hardness increase with increase fluence, while the matrix hardness does not change obviously. Raman spectrum shows the molecular bond was destroyed since the lowest fluence and it was characterized by SEM that the sample surface structure is almost stable even at the most serious case.