Reinforcement of Al2O3/TiC ceramic tool material by multi-layer graphene

The reinforcing effect of multi-layer graphene (MLG) on the fracture toughness and flexural strength of an Al2O3/TiC ceramic tool material was studied by theoretical analyses and experimental observations. The crack paths induced by Vickers indentation were analyzed using the fractal method to distinguish the possible reinforcing mechanisms. High-level reinforcement was observed in the Al2O3/TiC ceramic with well-dispersed MLG. The average indentation fracture toughness was 6.14 MPa m(1/2), against 4.98 MPa m(1/2) for the Al2O3/TiC ceramic, and the flexural strength improved from 749.6 MPa to 981.5 MPa for the 0.2 wt%-added MLG. The main reinforcing mechanisms are proposed to be the hindering effect of MLG on the crack path and the synergistic effect of weak and strong bonding interfaces, as well as grain refinement.