Toughening of silicon nitride ceramics by addition of multilayer graphene
| Autor: | János Szépvölgyi, Eszter Bódis, Péter Németh, Ildikó Cora, Zoltán Károly, Orsolya Tapasztó, Miklós Mohai, Sára Tóth |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Composite number Spark plasma sintering 02 engineering and technology 01 natural sciences law.invention chemistry.chemical_compound Fracture toughness law 0103 physical sciences Materials Chemistry Ceramic Composite material Porosity 010302 applied physics Graphene Process Chemistry and Technology 021001 nanoscience & nanotechnology Microstructure Surfaces Coatings and Films Electronic Optical and Magnetic Materials Silicon nitride chemistry visual_art Ceramics and Composites visual_art.visual_art_medium 0210 nano-technology |
| Zdroj: | Ceramics International. 45:4810-4816 |
| ISSN: | 0272-8842 |
| Popis: | Silicon nitride (Si3N4) ceramics have superior mechanical properties allowing their broad application in many technical fields. In this work, Si3N4-based composites with 1–5 wt% multilayer graphene (MLG) content were fabricated by spark plasma sintering at different temperatures and holding time in order to improve the fracture resistance of the Si3N4 ceramic. Our investigation focused on understanding the relationships between the microstructure and mechanical properties with special attention to the intergranular phases between Si3N4 matrix and MLG reinforcement. We have found that nanopores developed at the Si3N4-MLG interface due to a reaction between carbon and the oxygen available in the topmost layer of the Si3N4 particles. Interface porosity has an optimum for the toughening effect. In 1 wt% MLG/Si3N4 composites nanopores are local, but separated at the Si3N4-MLG interface, which promote the MLG pull-out mechanism imparting a significant toughening effect on the composite. Beyond the optimal 1 wt% MLG content, MLG platelets agglomerate and excessive porosity are developed at the Si3N4-MLG interfaces, leading to weaker matrix- graphene adhesion and thus lower fracture toughness. |
| Databáze: | OpenAIRE |
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