Synthesis and characterization of Al2O3-TiC-ZrO2 ceramics with intragranular nanostructure by spark plasma sintering

In this paper, Al2O3-TiC ceramic composites with intragranular nano-ZrO2 were prepared in vacuum by spark plasma sintering (SPS). The effect of ZrO2 particles with different nano-sizes on the microstructure and mechanical properties of ceramics was studied. The results show that SPS can achieve relative densification of materials without generating new impurity phases. At the same time, the sintering densification temperature of ceramic materials can be reduced by adding ZrO2 (20 nm) particles. Under the action of SPS strong electric field, the nano-ZrO2 adsorbed on the surface of the matrix particles can enter the interior of matrix grains, and form intragranular nanostructures when the grain boundaries move and the particles merge. The microstructure and mechanical properties of ceramic materials can be improved through the intragranular structure formed by nanoparticles. The main reasons for the increased strength and toughness of ceramic materials are crack deflection, crack bridging and transgranular fracture.

Automated summary

In this study, Al2O3-TiC ceramic composites with intragranular nano-ZrO2 were successfully prepared by using spark plasma sintering (SPS) technique in a vacuum environment. The impact of ZrO2 particles with different nano-sizes on the microstructure and mechanical properties of ceramics was investigated. The results demonstrate that SPS can achieve relative densification of materials without generating new impurity phases. Moreover, the addition of ZrO2 (20 nm) particles can lower the sintering densification temperature of ceramic materials. By utilizing the strong electric field generated by SPS, the nano-ZrO2 particles adsorbed on the surface of the matrix particles can penetrate into the interior of matrix grains, forming intragranular nanostructures when the grain boundaries migrate and the particles fuse. The microstructure and mechanical properties of ceramic materials can be enhanced through the formation of intragranular structures composed of nanoparticles. The increased strength and toughness of the ceramic materials are mainly attributed to crack deflection, crack bridging, and transgranular fracture.