Silicon nitride+1wt% graphene platelet composites were prepared using various graphene platelets (GPLs) as filler. The influence of the addition of GPLs on the microstructure development and on the fracture toughness of Si 3N 4+GPLs composites was investigated. The GPLs with thickness from 5nm to 50nm are relatively homogeneously distributed in the matrix of all composites, however overlapping/bundle formation of GPLs was found, containing 2-4 platelets as well. The single GPLs and overlapped GPLs are located at the boundaries of Si 3N 4, and hinder the grain growth and change the shape of the grains. The fracture toughness was significantly higher for all composites in comparison to the monolithic Si 3N 4 with the highest value of 9.9MPam 0.5 for the composite containing the GPLs with smallest dimension. The main toughening mechanisms originated from the presence of graphene platelets, and responsible for the increase in the fracture toughness values are crack deflection, crack branching and crack bridging.
|Number of pages||9|
|Journal||Journal of the European Ceramic Society|
|Publication status||Published - szept. 1 2012|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry