Deformation mechanisms of flash sintered yttria-stabilized zirconia via in situ micromechanical testing

Flash sintering has been applied to sintering a variety of ceramic materials. However, the mechanical behavior of flash-sintered ceramics is less well understood. In this study, the deformation mechanisms of flash-sintered yttria stabilized zirconia (YSZ) were investigated via in-situ microcompression test at temperatures of 25 to 650oC. The flash sintered YSZ exhibits high fracture strain due to transformation induced toughening below the test temperatures of 400oC. At higher temperatures, crack nucleation and propagation are significantly retarded, and no more catastrophic failures are observed. Strain rate jump tests were also performed at elevated temperature (450 ~ 650oC) to investigate the temperature dependent deformation mechanisms. The activation energy for deformation and its implication are discussed