Microstructure and mechanical properties of boron nitride nanosheets reinforced eutectic-composition Al2O3/YAG/YSZ composites

BNNSs were prepared efficiently by magnesium borate nitridation. BNNSs/eutectic-composition Al2O3/YAG/YSZ ceramics were prepared by hot pressing sintering. The addition of BNNSs did not change the phase composition of BNNSs/eutectic-composition Al2O3/YAG/YSZ ceramics. The bending strength and fracture toughness of 1.5wt%BNNSs/ eutectic-composition Al2O3/YAG/YSZ ceramic were increased by 19.0% and 18.9% respectively. Doped BNNSs exist at the grain boundary between two or more different grains. The toughening mechanism of BNNSs contains mainly crack deflection, BNNSs pullout and BNNSs bridging. •BNNSs/eutectic-composition Al2O3/YAG/YSZ ceramics were originally prepared with excellent mechanical properties.•The toughening mechanism of BNNSs was discussed.•The effects of temperature and BNNSs doping amount on the mechanical properties of ceramics were explored.