Fabrication and mechanical properties of nano-/micro-sized Al2O3/SiC composites

The processing and mechanical behavior of Al2O3 composites with 1-20 wt.% nano-/micro-sized SiC particles was investigated. The composites were densified by hot-pressing. The mechanical properties of nano-/micro-sized SiC/Al2O3 composites including hardness, fracture toughness and flexural strength were investigated. It was found that the fracture strength and fracture toughness of the nano-/micro-sized SiC/Al2O3 composites were significantly improved in comparison with the monolithic Al2O3. 7.6 MPa m1/2 was the highest fracture toughness and was found in the composite with 5% SiC, while the 20% SiC composite exhibited the highest flexural strength. The toughening and strengthening mechanisms of the ceramic composites were discussed.