Microstructural development in cubic silicon carbide during irradiation at elevated temperatures

Microstructural development in chemically vapor-deposited (CVD) high-purity beta-SiC during neutron and self-ion irradiation at elevated temperatures was studied. The CVD SiC samples were examined by transmission electron microscopy following neutron irradiation to 4.5-7.7 x 10(25) n/m(2) (E > 0. 1 MeV) at 300 and 800 degrees C and 5.1 MeV Si2+ ion irradiation up to similar to 200 dpa at 600-1400 degrees C. The evolution of various irradiation-produced defects including black spot defects, dislocation loops, network dislocations, and cavities was characterized as a function of irradiation temperature and fluence. It was demonstrated that the black spot defects and small dislocation loops continue to dominate at relatively low temperatures (<similar to 800 degrees C), whereas they grow into Frank faulted loops and finally develop into dislocation networks at a higher temperature (1400 degrees C). Substantial cavity formation on grain boundaries and stacking faults was confirmed after ion irradiation at 1400 degrees C. These observations were discussed in relation with the known irradiation phenomena in SiC, such as low temperature swelling and cavity swelling. (c) 2006 Elsevier B.V. All rights reserved.