Enhanced irradiation-resistance of polymer-derived SiC by incorporation of multiwalled carbon nanotubes

In this work, multiwalled carbon nanotubes were introduced into polycarbosilane to fabricate carbon nanotubes reinforced nano-SiC composites (MWCNTs/ PCS-nano-SiC). Radiation effects on MWCNTs/ PCS-nano-SiC were studied by irradiation with 2 MeV Au2+ ions at room temperature and doses ranging from 2 × 1014 to 8 × 1014 ions/cm2. The sample pyrolyzed at 1400 °C and containing 3 wt% carbon nanotubes exhibited excellent overall performances. The multiple graphite layers in the MWCNTs provided "absorption traps" for defects, improving the efficiency of defect recombination. Tightly combined MWCNTs/ PDC interface is required to enable the two phases to protect each other during irradiation. The critical amorphization dose was increased upon structural optimization, and the hardness degradation was significantly reduced. The rise of Young's modulus at a high damage dose was discovered because of the "interface-driven shrinkage" of nano-SiC. The present study provides insight into SiCf/ SiC design for an advanced nuclear system.