Enhanced irradiation stability of BN particles dispersed SiC under pressurized-water reactor related conditions

Neutron-induced radioactivity and response to atomic displacement damage of hexagonal boron nitride (h-BN) particles dispersed silicon carbide (SiC) materials prepared by liquid-phase sintering (LPS) were studied. These h-BN particles dispersed LPS-SiC materials are used as weak matrix for SiC_f/SiC composites without interphase materials to improve the resistance to corrosion and to lower the cost of the SiC_f/SiC composites. The Monte Carlo simulation results indicate that the LPS-SiC-20vol%BN composite with B as ¹¹B and N as ¹⁵N exhibits acceptable neutron-induced radioactivity in the PWR-related environments. Monolithic LPS-SiC-20vol%BN specimens were then irradiated to PWR-related damage level (0.1/1/3 displacement per atom, dpa, at 300 °C) with 5.1 MeV Si²⁺ ions. Addition of BN particles reduced the irradiation-induced swelling of LPS-SiC. Partial irradiation induced amorphization of h-BN, and partial phase transition of h-BN to c-BN were also found. This study is also helpful for understanding the irradiation effect of other composites containing BN.