Prediction of crack depth during quenching test for an ultra high temperature ceramic

摘要

Quenching test was used to characterize thermal shock properties of ZrB_2-20%SiC_p-10%AIN. It showed that critical temperature difference was 400 ℃, and residual strength was a constant while quenching temperature was higher than 400 ℃. Inertial stress was investigated under different temperatures, as shown, a higher temperature led to a lower inertial stress. Crack resistance under room temperature was compared with that under 600 ℃. as can be seen, a higher temperature led to a higher crack resistance. Dynamic thermal stress intensity factor was investigated at the quenching temperature of 600 ℃, and it indicated that stress intensity factor ascended first and descended afterwards, farther crack propagation would not occur when Biot value is in a certain range, such as Biot = 5. Crack would not propagate when Biot= 1, and specimen would be destroyed when Biot= 10.