High-velocity impact damage by projectile and tension after impact behavior at 1300 C for SiC/SiC with environment barrier coating

The research on the high-speed & low -energy impact under millimetre sized projectile and residual strength under high temperature are rare for SiC/SiC with Environmental Barrier Coatings (EBC). The impact of 2 mm steel projectiles at the speed of 177.5 m/s-252.7 m/s was studied for EBC(Si/Yb2Si2O7/Yb2SiO5)-SiC/SiC with Chemical Vapor Infiltration (CVI) process. The tensile test at 1300 degrees C was conducted on an inert gas protection testing machine. The optical microscope, Scanning Electronic Microscope(SEM), mu CT were used to observe the impact and tension after impact(TAI) damage. The results shows that projectile impact has strong effect on EBC peeling, SiC/SiC damage and fracture, and residual -tension strength at 1300 degrees C. And the threshold values of impact velocity or energy are different for them. Furthermore, an analysis method for damage evolution by the attachment quantity of oxide was found for EBC-SiC/SiC composites.