Enhancement of the mechanical properties of nacre-like alumina ceramic by the synergism of graphene oxide and Si3N4 whisker

Abstract

Synergic effect of graphene oxide (GO) and silicon nitride whisker (Si 3 N 4 w) on the mechanical properties of nacre-like alumina was investigated in this study. A comprehensive analysis on the composites, including microstructure, relative densities, flexural strength and fracture toughness, was carried out. The experimental results showed that, GO promoted the fracture toughness of the composites, but reduced the flexural strength slightly; while adding a certain amount of Si 3 N 4 w improved both flexural strength and fracture toughness. With the incorporation of GO and Si 3 N 4 w, the highest flexural strength reached 520 MPa and the fracture toughness reached 9.59 MPa m 1/2 . Microstructure observation revealed that the enhanced mechanical properties were ascribed to the synergistic toughening mechanisms induced by the nacre-like structure of alumina, GO pull-out, Si 3 N 4 w pinning and pull-out.