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

Abstract

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.