Graphene reinforced alumina nano-composites

0421478 - ÚFM 2014 RIV GB eng J - Journal Article
Porwal, H. - Tatarko, Peter - Grasso, S. - Khaliq, J. - Dlouhý, Ivo - Reece, M.J.
Graphene reinforced alumina nano-composites.
Carbon. Roč. 64, NOV (2013), s. 359-369. ISSN 0008-6223. E-ISSN 1873-3891
R&D Projects: GA MŠMT(CZ) ED1.1.00/02.0068
EU Projects: European Commission(XE) 264526 - GLACERCO
Institutional support: RVO:68081723
Keywords : fracture toughness determination * ceramic-matrix composites * carbon nanotubes
Subject RIV: JI - Composite Materials
Impact factor: 6.160, year: 2013

Graphene was prepared using liquid phase exfoliation and dispersed in an alumina matrix using an ultrasonication and powder processing route. Al2O3–graphene composites with up to 5 vol% content were densified (>99%) using SPS. The fracture toughness of the materiál increased by 40% with the addition of only 0.8 vol% graphene. However for higher graphene contents the improvement in fracture toughness was limited. Graphene changed the mechanism of crack propagation for the alumina matrix from inter-granular to trans-granular. The formation of an inter-connecting graphene network promoted easy fracture for concentration P2 vol%. Elastic modulus remained nearly constant for up to 2 vol% and decreased significantly for 5 vol% due to the formation of the inter-connecting graphene network. Fracture toughness measured with the indentation and chevron notch methods were consistent up to 2 vol% and at 5 vol% the percolating network of graphene resulted in easy crack propagation with significant discrepancy between the results for the two methods.
Permanent Link: http://hdl.handle.net/11104/0228002