High temperature deformability of ductile flash-sintered ceramics via in-situ compression

Flash sintering has attracted significant attention as its remarkably rapid densification process at low sintering furnace temperature leads to the retention of fine grains and enhanced dielectric properties. However, high-temperature mechanical behaviors of flash-sintered ceramics remain poorly understood. Here, we present high-temperature (up to 600 degrees C) in situ compression studies on flash-sintered yttria-stabilized zirconia (YSZ). Below 400 degrees C, the YSZ exhibits high ultimate compressive strength exceeding 3.5 GPa and high inelastic strain (similar to 8%) due primarily to phase transformation toughening. At higher temperatures, crack nucleation and propagation are significantly retarded, and prominent plasticity arises mainly from dislocation activity. The high dislocation density induced in flash-sintered ceramics may have general implications for improving the plasticity of sintered ceramic materials.