Effect of the Al₂O₃ content on the microstructure evolution of flash-sintered Al₂O₃-8YSZ ceramics

Systematic explorations of complex insulator-conductor composites may help in better comprehending the nature of flash sintering. In this study, flash sintering of alumina-8 mol% yttria stabilized zirconia (Al2O3-8YSZ) binary system with different mixing molar ratios was investigated. The results indicate that Al2O3 content significantly affects the flash-sintering behavior of Al2O3-8YSZ ceramics. The onset temperature of flash sintering increased with the increase in the Al2O3 content under 900 V cm(-1). For the Al2O3 content above 20 mol%, Al2O3-8YSZ multiphase ceramics with eutectic morphology could be obtained at 800 degrees C-700 V.cm(-1)-120 s. Eutectic structures with different morphologies were obtained by adjusting the content of Al2O3. Formation of the eutectic structures is related to the Joule heating and defects introduced by the electric field. Flash sintering is a promising and novel sintering technology for the rapid fabrication of high-performance oxide eutectic ceramics.