Shock wave-material interaction in ZrB2-SiC based ultra high temperature ceramics for hypersonic applications

We investigate the thermochemical stability of ZrB2-SiC based multiphase ceramics to hypersonic aerothermodynamic conditions in free piston shock tube with an objective to understand quantitatively the role of thermal shock and pressure. The developed ceramics sustained impulsive thermomechanical shock, under reflected shock pressure of 6.5 MPa and reflected shock temperature of 4160 K in dissociated oxygen, without structural failure. The conjugate heat transfer analysis predicts the surface temperature of ZrB2-SiC to reach a maximum of 693 and 865 K, for ZrB2-SiC-Ti. The transient shock-material response is characterized by surface oxidation of the investigated ceramics, when exposed to high enthalpy gaseous environment, as a consequence of the interaction with ultrafast-heated (10(6) K/s) gas for ~5 ms. Spectroscopic and structural characterization reveals that addition of Ti improves thermomechanical shock resistance, which is attributed to the assemblage of refractory phases. Taken together, ZrB2-SiC-Ti based multiphase ceramics exhibit favorable shock-material response under impulse loading.