Journal of the American Ceramic Society, Vol.89, No.1, 266-273, 2006
Dynamic compressive response of damaged and interlocked SiC-N ceramics
The dynamic compressive responses of a damaged but interlocked hot-pressed silicon carbide were determined as a function of loading rates, damage, and confinement. A novel experimental technique based on a split Hopkinson pressure bar was used to conduct the high strain-rate experiments. The ceramic specimen was loaded by two consecutive stress pulses to determine the responses of the intact and damaged specimen under valid testing conditions. The results show that, once critically damaged, the compressive response of the damaged ceramic was insensitive to increasing strain rates and further damage but varied with increasing lateral confinement. Under 104-MPa confinement and damaged to three different levels, the flow stress remained at 1 GPa at strain rates of 600-1600 s(-1). The flow stress reduced to 500 and 350 MPa under confinement of 56 and 26 MPa respectively.