Microstructural characterization of Al2O3-SiC nanocomposites

Abstract Al 2 O 3 composite ceramics containing 10 vol% SiC nanoparticles were prepared by pressureless sintering. SiC particles 2 O 3 -SiC nanocomposites. The interaction between propagating cracks and internal stress fields around intragranular inclusions forces a transgranular fracture mode. Grain boundary pinning by large intergranular SiC particles, in combination with solute drag inhibits matrix grain growth, while the presence of an amorphous phase at Al 2 O 3 grain boundaries and Al 2 O 3 -SiC phase boundaries assists in densification. Excess liquid phase is exuded from the interfaces during consolidation and accumulates in large pores, stabilized by the accidental agglomeration of large SiC particles.