Experimental study on the dynamic mechanical behaviors of silicon carbide ceramic after thermal shock

Abstract

Abstract As a potential substitute material for metal and concrete in producing nuclear waste storage canisters, silicon carbide (SiC) can be subjected to various mechanical and thermal influences during its lifetime. To investigate the reliability of SiC in situ, especially in unusual cases involving impact load and high temperature, dynamic mechanical tests are performed on heated SiC utilizing the Split Hopkinson Pressure Bar (SHPB) system. Before the mechanical tests, thermal shock (TS) treatments are applied on the SiC specimens before the mechanical tests, where the heated specimens are cooled in air and water to provide different cooling rates. The test results indicate no discernable variation of dynamic compressive strength after heating at 100 °C. Evident drop of strength value is observed at heating levels higher than 200 °C. It is also found that with approximately the same incident energy, the energy absorbed by the specimen decreases with ascending cooling rate. The scanning electron microscopy (SEM) technique is also utilized to provide explanations for the corresponding test results whereby the damage mechanisms of thermal shock on SiC are analyzed.