Mechanical, Thermal, and Microstructural Properties of Neutron‐Irradiated SiC

Abstract

The thermal and electrical conductivities, fracture strength, swelling, and microstructure of sintered alpha‐phase Sic and siliconized reaction‐bonded Sic materials were studied before and after irradiation with reactor neutrons. The effects of helium gas on the properties were studied using boron enriched in ' O B to produce helium from 10 B(n, α) 7 Li. The decrease in thermal conductivity after irradiation is due to enhanced phonon scattering by radiation‐induced defects. Electrical, mechanical, and thermal properties exhibit partial recovery after heat treatment to 1000 to 1500 K. An overall consistency is observed in radiation‐produced property changes and annealing and a model is presented to explain the changes.