Radiation induced electrical and microstructural degradation at high temperature for HP SiC

Abstract

SiC based composites are candidates for possible use as structural materials, and flow channel inserts in Li–Pb tritium breeding blanket modules for DEMO and future fusion reactors. Previous studies showed noticeable changes in electrical conductivity and also amorphization after 1.8 MeV electron irradiation for irradiation temperatures between 290 and 650 °C. However this material is foreseen to be used at higher temperatures. In this work hot pressed (HP) SiC has been electron irradiated at temperatures up to 900 °C and the bulk electrical conductivity measured as a function of irradiation temperature and dose. Following irradiation modification of the microstructure was studied and the dependence on irradiation temperature addressed. It was found that the degradation of the material is lower for the higher irradiation temperature indicating that by about 900 °C the induced damage is efficiently annealed during irradiation.