Preparation and mechanical properties of Si 3 N 4 nanocomposites reinforced by Si 3 N 4 @rGO particles

A new type of reduced graphene oxide‐encapsulated silicon nitride (Si 3 N 4 @rGO) particle was synthesized via an electrostatic interaction between amino‐functionalized Si 3 N 4 particles and graphene oxide (GO). Subsequently, the Si 3 N 4 @rGO particles were incorporated into a Si 3 N 4 matrix as a reinforcing phase to prepare nanocomposites, and their influence on the microstructure and mechanical properties of the Si 3 N 4 ceramics was investigated in detail. The microstructure analysis showed that the rGO sheets were uniformly distributed throughout the matrix and firmly bonded to the Si 3 N 4 grains to form a three‐dimensional carbon network structure. This unique structure effectively increased the contact area and load transfer efficiency between the rGO sheets and the matrix, which in turn had a significant impact on the mechanical properties of the nanocomposites. The results showed that the nanocomposites with 2.25 wt.% rGO sheets exhibited mechanical properties that were superior to monolithic Si 3 N 4 ; the flexural strength increased by 83.5% and reached a maximum value of 1116.4 MPa, and the fracture toughness increased by 67.7% to 10.35 MPa·m 1/2 .