Volume 2, Issue 8 (September 2005)
Mechanical Properties of Cubic Silicon Carbide after Neutron Irradiation at Elevated Temperatures
Mechanical properties of high-purity polycrystalline cubic SiC was characterized after neutron irradiation. Bar samples were irradiated in target position capsules in the High Flux Isotope Reactor (HFIR, Oak Ridge, Tennessee) to nominal fluence levels up to 7.7 dpa at temperatures of 300, 500, and 800°C. A decrease in Young's modulus was observed after irradiation, and its irradiation temperature dependence qualitatively agreed with the calculated modulus change due to point defect swelling. Irradiation caused a significant modification of statistical flexural strength but caused only minor increase in nano-indentation hardness. The irradiation effect on fracture initiation through an enhanced cleavage resistance likely is primarily responsible for the major change in flexural strength properties.