Gallardo López, Ángela MaríaCastillo Seoane, JavierMuñoz Ferreiro, CarmenLópez Pernía, CristinaMorales Rodríguez, AnaPoyato Galán, Rosalía2020-06-172020-06-172020Gallardo López, A.M., Castillo Seoane, J., Muñoz Ferreiro, C., López Pernía, C., Morales Rodríguez, A. y Poyato Galán, R. (2020). Flexure Strength and Fracture Propagation in Zirconia Ceramic Composites with Exfoliated Graphene Nanoplatelets. Ceramics, 3 (1), 78-91.2571-6131https://hdl.handle.net/11441/97956In this work, the flexure strength and fracture propagation mechanisms in yttria tetragonal zirconia (3YTZP) dense composites with 1 and 5 vol.% exfoliated graphene nanoplatelets (e-GNP) were assessed. The composite powders were processed by dry planetary ball milling to exfoliate the as-received GNP, and then densified by spark plasma sintering (SPS). The hardness and Young’s modulus were measured by Vickers indentation and the impulse-echo technique, respectively. Flexural strength and modulus were estimated by four-point bending tests. Finally, cracks originated by Vickers indentations were analyzed by scanning electron microscopy (SEM). The Raman spectra and SEM observations showed a reduction in the number of graphene layers and most remarkably in the lateral size of the e-GNP, achieving a very homogeneous distribution in the ceramic matrix. The hardness, elastic modulus, and flexural strength of the 3YTZP matrix did not vary significantly with the addition of 1 vol.% e-GNP, but they decreased when the content increased to 5 vol.%. The addition of e-GNP to 3YTZP increased its reliability under bending, and the small lateral size of the e-GNP produced isotropic fracture propagation. However, the energy dissipation mechanisms conventionally attributed to the larger GNP such as fracture deflection or blocking were limited.application/pdf14 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/3YTZPGraphene nanoplatelets (GNP)Ceramic compositesPlanetary ball millingSPSRaman spectroscopyFlexural strengthFour-point bendingCrack propagationVickers indentationsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.3390/ceramics3010009