Synergistic Effect of Displacement Damage, Helium and Hydrogen of Silicon Carbide Composite

The mechanical properties of advanced SiC/SiC composite and polycrystalline, monolithic β-SiC under dual- and triple-ions irradiation to 1 and 10 dpa at 800 deg. C, 1000 deg. C, and 1300 deg. C were investigated by a Nano-indentation test. Preliminary microstructural analysis by transmission electron microscopy was performed. Hardness and elastic modulus changes in response to ion irradiation were observed, but synergistic effects on these mechanical properties were not significant. In contrast, microstructural observation of the composites after 10 dpa at 1000 deg. C showed that cavity formation behavior was dependent on the material and the helium or hydrogen implanted mode. The effect of gas elements on cavity formation and the mechanical properties are discussed