Наши публикации

Mechanical and biological evaluation of 3D printed 10CeTZP-Al2O3 structures

Journal of the European Ceramic Society, Volume 37, Issue 9, August 2017, Pages 3151–3158. WoS, Q1, IF=2.933

Abstract. Three-dimensional structures were robocasted from a 10 mol% ceria-stabilized zirconia and alumina composite (10CeTZP-Al2O3). A hydrogel-based printable ink was developed using a unique non-ionic copolymer surfactant. Self-supporting and free-standing structures, including round lattices with interconnected pores (200–600 μm pores; 30–50% porosity), rectangular bars (95% density on average) and cones were successfully printed. The round lattices of 200 μm pores and 30% porosity showed compression strengths similar to those of cortical bone, reaching almost 200 MPa. The maximum flexural strength value attained for the rectangular bars was 575 MPa. In vitro biological studies demonstrated that the samples allow for practically 100% cell viability, confirming their non-cytotoxic nature. Cell differentiation tests were performed using osteoblasts incubated for 7 days in supplemented cell culture medium. Quantification of specific osseous differentiation genes showed that the robocasted structures induced a higher degree of osseous differentiation than tissue culture polystyrene.

Keywords. 3D Printing; Robocasting; Ceramic composites; Scaffolds; Osseous differentiation

Round lattice design grid configurations: (a) simple pattern and (b) complex pattern. SEM images of (c) a sintered simple round lattice and (d) a sintered complex round lattice, both printed in air through a 580 m tips. (e) SEM image of the microstructure of a sintered round lattice ink filament.

Исполнители: Lidia Goyos-Balla, Esther García-Tuñón, Elisa Fernández-García, Raquel Díaz, Adolfo Fernández, Catuxa Prado, Eduardo Saiz, Ramón Torrecillas

Дата публикации: 04-03-2017

Источник: http://www.sciencedirect.com/science/article/pii/S0955221917301486

Electrically conductor black zirconia ceramic by SPS using graphene oxide

Journal of Electroceramics (2017) 38:119

Abstract. The use of graphene as a component for developing electroconductive ceramic composites is being profusely studied. It is a very promising additive as it has excellent mechanical properties, high electrical and thermal conductivities, it is lightweight and its aspect ratio allows reaching percolation with low contents. In the particular case of zirconia, preparation of black coloured materials remains a challenge while many high added value applications are waiting for a solution. Graphene appears as a candidate for fulfilling all these requirements. In this work, 3Y–TZP/rGO composites were prepared by Spark Plasma Sintering Zirconia-rGO mixtures. Simultaneous sintering and in-situ reduction of graphene oxide opens a very interesting technological route for preparing this type of materials. The influence of graphene content on the electrical, mechanical and optical properties was studied. An rGO content as low as 0,29 vol% allows nanostructured black zirconia to be obtained but it has to be increased up to 1 vol% in order to reach electrical resistivity values <100Ωcm, required for electrodischarge machining.

Keywords: Zirconia composites Graphene Spark plasma sintering Black zirconia

SEM micrograph of starting ZrO2-(0.39 wt% GO) powders (left) and fracture surface of ZrO2-(0,39 wt%) rGO composite (right)

Исполнители: N.W. Solís, P. Peretyagin, R. Torrecillas, A. Fernández, J. L. Menéndez, C. Mallada, L. A. Díaz and J. S. Moya

Дата публикации: 22-02-2017

Источник: https://link.springer.com/article/10.1007/s10832-017-0076-z

Unprecedented simultaneous enhancement in damage tolerance and fatigue resistance of zirconia/Ta composites

Scientific Reports 7, Article number: 44922 (2017)

Abstract. Dense (>98 th%) and homogeneous ceramic/metal composites were obtained by spark plasma sintering (SPS) using ZrO2 and lamellar metallic powders of tantalum or niobium (20 vol.%) as starting materials. The present study has demonstrated the unique and unpredicted simultaneous enhancement in toughness and strength with very high flaw tolerance of zirconia/Ta composites. In addition to their excellent static mechanical properties, these composites also have exceptional resistance to fatigue loading. It has been shown that the major contributions to toughening are the resulting crack bridging and plastic deformation of the metallic particles, together with crack deflection and interfacial debonding, which is compatible with the coexistence in the composite of both, strong and weak ceramic/metal interfaces, in agreement with predictions of ab-initio calculations. Therefore, these materials are promising candidates for designing damage tolerance components for aerospace industry, cutting and drilling tools, biomedical implants, among many others.

Keywords: ceramic/metal composite, spark plasma sintering, zirconia. lamellar metallic powders of tantalum or niobium, properties, microstructure

FIB-SEM image of crack propagation in the zirconia-tantalum composite. Arrows indicate interface debonding between the metal particles and the ceramic (A), plastic deformation (B) and crack bridging of ligament (B).

Исполнители: A. Smirnov, J. I. Beltrán, T. Rodriguez-Suarez, C. Pecharromán, M. C. Muñoz, J. S. Moya and J. F. Bartolomé

Дата публикации: 14-02-2017

Источник: https://www.nature.com/articles/srep44922