Gallardo López, Ángela MaríaMorales Rodríguez, AnaMárquez Abril, IvánMuñoz Bernabé, AntonioPoyato Galán, Rosalía2023-05-262023-05-262017Gallardo López, Á.M., Morales Rodríguez, A., Márquez Abril, I., Muñoz Bernabé, A. y Poyato Galán, R. (2017). Dense graphene nanoplatelet/yttria tetragonal zirconia composites: Processing, hardness and electrical conductivity. Ceramics International, 43 (15), 11743-11752. https://doi.org/10.1016/j.ceramint.2017.06.007.0272-8842https://hdl.handle.net/11441/146698Yttria tetragonal zirconia ceramic composites with 1, 2.5, 5 and 10 vol% nominal contents of graphene nanoplatelets (GNPs) were fabricated and characterized. First, the GNP dispersion in isopropanol was optimized to de-agglomerate the GNPs without damaging their structure. Then, submicrometric fully dense composites were obtained via spark plasma sintering (SPS) at 1250 °C with a 5 min holding time. The processing routine produced a nearly homogeneous GNP dispersion in the ceramic matrix, and the GNPs preferential orientation was perpendicular to the sintering compression axis. A ceramic grain refinement due to the GNPs was also detected. The Vickers hardness measured on the plane perpendicular to the sintering compression axis (basal plane) was lower than on the cross sections. This anisotropy increased with the increasing GNP content, while the average hardness decreased. The electrical conductivity was also highly anisotropic, up to seven times higher for the basal planes. The electrical percolation threshold for these composites was estimated to be between 2.2 and 4.4 vol% of the GNP measured content.application/pdf14 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Ceramic composites3YTZPGraphene nanoplateletsProcessingMicrostructureinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1016/j.ceramint.2017.06.007