The influence of TiC-particle-size on the fracture toughness of Al2O3–30 wt.%TiC composites

Seven grades of Al2O3–30 wt.% TiC composites were prepared by hot-pressing the Al2O3 powder mixed with TiC particles. The average sizes of the TiC particles used for preparing these composites were different with each other. The fracture toughness KIC was measured in three-point bending for each composite. It was shown that the variation in the size of the TiC particles results in large changes in fracture toughness and there is a particular particle size for which the fracture toughness of the resultant composite reaches its maximum. A possible toughening mechanism was also proposed to explain these experimental findings.