Mechanical properties of graphene platelet-reinforced alumina ceramic composites

Alumina (Al2O3) ceramic composites reinforced with graphene platelets (GPLs) were prepared using Spark Plasma Sintering. The effects of GPLs on the microstructure and mechanical properties of the Al2O3 based ceramic composites were investigated. The results show that GPLs are well dispersed in the ceramic matrix. However, overlapping of GPLs and porosity within ceramics are observed. The flexural strength and fracture toughness of the GPL-reinforced Al2O3 ceramic composites are significantly higher than that of monolithic Al2O3 samples. A 30.75% increase in flexural strength and a 27.20% increase in fracture toughness for the Al2O3ceramic composites have been achieved by adding GPLs. The toughening mechanisms, such as pull-out and crack deflection induced by GPLs are observed and discussed.