Radiation Resistance of Nanocrystalline Silicon Carbide

Silicon carbide is known for its superior thermomechanical performance, corrosion resistance, and radiation resistance. The radiation resistance of silicon carbide nanopowders with sizes of 10nm and 45nm-55 nm diameter, as well as bulk silicon carbide (grain size ~ 1μm), have been investigated in situ in the IVEM-Tandem facility at Argonne National Laboratory. The particles were irradiated with 1.0 MeV Kr⁺ ions over a series of temperatures and doses. The radiation resistance was studied by observing changes in the critical amorphization dose. The 10nm particle size required a lower dose to amorphize at 100°C than either the 45-55nm particles or the bulk silicon carbide. This observation indicates a weakened radiation response with decreasing grain size at temperatures above 100°C. Below 100°C no difference in amorphization behavior was observed with changing grain size. Ex situ ion irradiations of thin film nanocrystalline silicon carbide using 2.0 MeV C²⁺ ions, up to 10 dpa at 600°C showed no evidence of amorphization of the original crystalline structure.