title: Toughened and machinable glass matrix composites reinforced with graphene and graphene-oxide nano platelets.
abstract: The processing conditions for preparing well dispersed silica-graphene nanoplatelets and silica-graphene oxide nanoplatelets (GONP) composites were optimized using powder and colloidal processing routes. Fully dense silica-GONP composites with up to 2.5 vol% loading were consolidated using spark plasma sintering. The GONP aligned perpendicularly to the applied pressure during sintering. The fracture toughness of the composites increased linearly with increasing concentration of GONP and reached a value of ∼0.9 MPa m1/2for 2.5 vol% loading. Various toughening mechanisms including GONP necking, GONP pull-out, crack bridging, crack deflection and crack branching were observed. GONP decreased the hardness and brittleness index (BI) of the composites by ∼30 and ∼50% respectively. The decrease in BI makes silica-GONP composites machinable compared to pure silica. When compared to silica-Carbon nanotube composites, silica-GONP composites show better process-ability and enhanced mechanical properties.
authors.affiliation: School of Engineering and Material Science, Queen Mary University of London, London E1 4NS, UK; Nanoforce Technology Limited, London, E1 4NS, UK.
authors.forename: Harshit
authors.initials: H
authors.lastname: Porwal
authors.affiliation: Institute of Physics of Materials, ASCR, CEITEC IPM, Zizkova 22, 616 62 Brno, Czech Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Tatarko
authors.affiliation: School of Engineering and Material Science, Queen Mary University of London, London E1 4NS, UK; Nanoforce Technology Limited, London, E1 4NS, UK.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Grasso
authors.affiliation: Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, People's Republic of China.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Hu
authors.affiliation: Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstraße 6, D-91058 Erlangen, Germany.
authors.forename: Aldo R
authors.initials: AR
authors.lastname: Boccaccini
authors.affiliation: Institute of Physics of Materials, ASCR, CEITEC IPM, Zizkova 22, 616 62 Brno, Czech Republic.
authors.forename: Ivo
authors.initials: I
authors.lastname: Dlouhý
authors.affiliation: School of Engineering and Material Science, Queen Mary University of London, London E1 4NS, UK; Nanoforce Technology Limited, London, E1 4NS, UK.
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Reece
keywords: graphene/graphene-oxide nanoplatelets; mechanical properties; nanocomposites; silica; sintering