Measurement of the mechanical properties of thermally-shocked zirconia-based simulated inert matrix fuel

The Vickers micro-hardness (Hv) was measured by an indentation technique of simulated ZrO2-based Inert Matrix Fuel (IMF) material with a composition o f Er0.07Y0.10Ce0.15Zr0.68O1.915 in two different densities on sintered spec imens and specimens thermally shocked with the quenching temperature differ ences (Delta Ts) between 473 and 1673 K and compared with those of simulate d MOX, namely, U0.92Ce0.08O2. The H-v values obtained for two IMF materials were found higher, ranging from 6.37 GPa to about 7.84 GPa, depending on D eltaT and the sintered density, than those obtained for the simulated MOX w hich are quasi-constant in the same range of DeltaT with a mean value of 6. 37 GPa. The fracture toughness (K-IC) was calculated from the measured H-v and the crack length, and it was found to exhibit a slight increase with in creasing DeltaT, ranging between 1.4 and 2.0 MPa m(1/2), while that of simu lated MOX specimen is ranging between 0.8 and 1.1 MPa m(1/2). The thermally shocked specimens were observed with an optical microscope and analyzed in terms of microstructural changes and cracking patterns. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.