The influence of sintering additives on the irradiation resistance of NITE SiC

The effects of sintering additives on irradiation swelling and modulus for monolithic NITE SiC was studied using 5.1 MeV Si2+ ion irradiation up to 5 dpa at 553–1273 K. The elastic modulus of NITE SiC decreased less than ∼7% in the highest damage case of 553 K, 3 dpa, indicating that the additives did not negatively affect the modulus of irradiated NITE SiC. A sample containing 9% additives showed higher swelling rates than high purity CVD SiC at lower temperatures. At 553 K, 5 dpa, the swelling of NITE SiC (9 wt.%) was twice as large as that of CVD SiC. Analysis of the electron diffraction patterns showed amorphization of the secondary phase, which is likely a primary reason for the increased swelling.