▎ 摘　　要

Silicon nitride + 1 wt.% graphene platelet composites were prepared using various graphene platelets with the aim to improve the fracture toughness of Si3N4. The fracture toughness was significantly higher for all composites in comparison to the monolithic Si3N4, with the highest value of 9.92 MPa m(0.5). The main toughening mechanisms originated from the presence of graphene platelets, and the increase in the fracture toughness values was attributable to crack deflection, crack branching and crack bridging. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.