Novel water-based processing of graphene oxide and sub-micrometric alumina towards tougher and electrically-conductive structural ceramics

Balancing the mechanical and functional properties of graphene-reinforced ceramics can be a challenge because agglomeration of the reinforcement must be avoided to minimise microstructural defects and it is difficult to organise the constituents into meaningful structures. The water-based processing...

Descripción completa

Detalles Bibliográficos
Autores: Alemzadeh, Joseph, Benavente, Rut, Borrell, Amparo, Gutiérrez-González, C. F., Suárez, Marta, Díaz, Luis A., Montes Morán, Miguel Ángel, Blanco Rodríguez, Clara, Evans, Sam L., Rocha, Victoria G.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/391390
Acceso en línea:http://hdl.handle.net/10261/391390
Access Level:acceso abierto
Palabra clave:Graphene
Alumina
Ceramic-based composites
Freeze-casting
Spark plasma sintering
Descripción
Sumario:Balancing the mechanical and functional properties of graphene-reinforced ceramics can be a challenge because agglomeration of the reinforcement must be avoided to minimise microstructural defects and it is difficult to organise the constituents into meaningful structures. The water-based processing strategy that is demonstrated here illustrates the potential to fabricate layered alumina composites using a combination of freeze-casting, vacuum infiltration, and spark plasma sintering. Layers of alumina between 0.5 and 7 μm thick and consist of an average grain size of 0.7 ± 0.4 μm were separated by highly-oriented reduced graphene oxide. Mechanical and functional properties were investigated alongside a monolithic counterpart sintered at 1300 °C. The flexural strength and fracture toughness increased from 262 to 314 MPa and 3.5–5.4 MPa m1/2 respectively, whilst electrical conductivity rose by nine orders of magnitude to 10−1 S cm−1.