scholarly journals Spark Plasma Sintered Zirconia Ceramic Composites with Graphene-Based Nanostructures

Ceramics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 153-164 ◽  
Author(s):  
Ángela Gallardo-López ◽  
Cristina López-Pernía ◽  
Carmen Muñoz-Ferreiro ◽  
Carmen González-Orellana ◽  
Ana Morales-Rodríguez ◽  
...  
Keyword(s):  
Powder Processing ◽  
Tetragonal Zirconia ◽  
High Energy ◽  
Ceramic Composites ◽  
Homogenization Method ◽  
Zirconia Ceramic ◽  
Dry Conditions ◽  
Spark Plasma ◽  
Composite Microstructure ◽  
Ultrasound Sonication

The addition of graphene-based nanostructures (GBNs) can improve the inherent fragility of ceramics and provide them with improved electrical and thermal conductivities. However, both the starting material (ceramic matrix and GBNs) and the processing/sintering approach are crucial for the final composite microstructure and properties. This work focuses on the influence of the content and dimensions of the GBN filler (10 and 20 vol%; 3 and ~150 layers), the powder-processing conditions (dry versus wet), and the homogenization method (ultrasound sonication versus high-energy planetary ball milling) on GBN/tetragonal zirconia (3YTZP) composites. The microstructure and electrical properties of the spark plasma sintered (SPS) composites were quantified and analyzed. The highest microstructural homogeneity with an isotropic microstructure was achieved by composites prepared with thicker GBNs milled in dry conditions. A high content (20 vol%) of few-layered graphene as a filler maximizes the electrical conductivity of the composites, although it hinders their densification.

Improving Mechanical Properties of Ceramic Composites by Harmonic Microstructure Control

2014 ◽  
Vol 896 ◽  
pp. 570-573 ◽  
Author(s):  
Lydia Anggraini ◽  
Ryohei Yamamoto ◽  
Kazuma Hagi ◽  
Hiroshi Fujiwara ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Milling Time ◽  
Milled Powder ◽  
High Energy ◽  
Ceramic Composites ◽  
Design Tool ◽  
Powder Mixtures ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Relationship Of

In this research, several ceramic composites such as SiC-ZrO2, Al2O3-ZrO2, and Si3N4-ZrO2containing nominally equal ratio 1:1 were prepared through high energy mechanical milling and spark plasma sintering. The relationship of microstructure and mechanical properties were investigated. Harmonic microstructures consisting of fine and ultra-fine grains forming a network were obtained by the optimum milling time for 144ks with high mechanical properties. The non-milled powder mixtures and too long milling time powder mixtures have low mechanical properties sintered by spark plasma. The crack propagates through ultra-fine grains and deflected by larger fine grains were obtained on the harmonic microstructure sample resulting in high toughness. Thus, the harmonic microstructure can be considered a remarkable design tool for improving the mechanical properties of SiC-ZrO2, Al2O3-ZrO2, and Si3N4-ZrO2as well as other ceramic composites.

Effect of Particle Shape on Dispersion Formation of Harmonic Microstructure of Si3N4-ZrO2

2016 ◽  
Vol 864 ◽  
pp. 47-51 ◽  
Author(s):  
Lydia Anggraini ◽  
Yuta Natsume ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Milling ◽  
Bending Strength ◽  
Powder Processing ◽  
Ceramic Matrix Composites ◽  
Zirconia Ceramic ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Particle Shapes

Silicon nitride with 50 mass zirconia ceramic matrix composites were processed by mechanical milling (MM) followed by spark plasma sintering (SPS). Two different of Si3N4 particle shapes for create harmonic microstructure were investigated. The microstructure of Si3N4-ZrO2 with initial Si3N4 shape is like coin/flakes after MM for 144 ks was failed to create the harmonic microstructure after SPS. With another sphere shape of Si3N4 after MM for 144 ks, the harmonic microstructure could be formed after SPS. Thus, the initial powders shape of Si3N4 have an effect in the formation of harmonic microstructure could be fully achieved. The highest mechanical properties of Si3N4-ZrO2 are on the powders with mechanical milling time for 144 ks. The Si3N4 ceramic with homogeneous fine grains of ZrO2 dispersed on its surface was obtained, and the mechanical properties were improved. The Vickers hardness obtained on 144 ks is 1031 MPa and the bending strength is 262 MPa. The main factors explaining the improvement in the mechanical properties of Si3N4-ZrO2 are considered to be the porosity decrease caused by the particles shape and appropriate condition of powder processing i.e. MM and SPS.

Processing of Swnt-Reinforced Yttria Stabilized Zirconia by Spark Plasma Sintering and Microstructure Characterization

2012 ◽  
Vol 18-19 ◽  
pp. 317-323 ◽  
Author(s):  
S. de Bernardi-Martín ◽  
R. Poyato ◽  
Diego Gómez-García ◽  
Arturo Domínguez-Rodríguez
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Yttria Stabilized Zirconia ◽  
Zirconia Ceramic ◽  
Stabilized Zirconia ◽  
Single Wall Carbon ◽  
Plasma Sintering ◽  
Spark Plasma

Single wall carbon nanotube reinforced yttria stabilized zirconia ceramic materials have been obtained by means of spark plasma sintering technique. Single wall carbon nanotubes were treated in an acid solution before mixing with zirconia powders to obtain a uniform distribution of both powders. This method allows obtaining ceramic materials with a grain size between 200 nanometers and 1 micron and with a grain size distribution which depends on processing conditions. This new route opens a new perspective for new ceramic composites tailoring with enhanced mechanical properties as structural materials

scholarly journals Critical Influence of the Processing Route on the Mechanical Properties of Zirconia Composites with Graphene Nanoplatelets

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 108
Author(s):  
Ángela Gallardo-López ◽  
Carmen Muñoz-Ferreiro ◽  
Cristina López-Pernía ◽  
Emilio Jiménez-Piqué ◽  
Felipe Gutiérrez-Mora ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Processing ◽  
Tetragonal Zirconia ◽  
Cost Effective ◽  
Ceramic Composites ◽  
Graphene Nanoplatelets ◽  
Processing Route ◽  
Plasma Sintering ◽  
Structural Applications ◽  
Need To Evaluate

Graphene-based nanostructures, used as potential reinforcement in ceramic composites, have a great tendency to agglomerate. This requires the use of homogenization techniques during the powder processing, posing the need to evaluate how these techniques affect the microstructure and the mechanical properties of the resulting composites. The influence of the processing route on the properties of 3YTZP (3 mol % yttria tetragonal zirconia polycrystals) ceramic composites with 10 vol % cost-effective GNP (graphene nanoplatelets) has been addressed. Four different powder processing routines combining ultrasonic powder agitation (UA) and planetary ball milling (PBM) in wet and dry media have been used and all the composites were densified by spark plasma sintering (SPS). The mechanical properties at room temperature in the macroscale have been assessed by Vickers indentations, four-point bending tests and the impulse-echo technique, while instrumented indentation was used to measure the hardness and Young’s modulus at the nanoscale. The application of dry-PBM enhances greatly the mechanical and electrical isotropy of the composites, slightly increases the hardness and lowers the elastic modulus, independently of the application of UA. The combination of UA and dry-PBM enhances the flexure strength by 50%, which is desirable for structural applications.

scholarly journals An Engineering Zirconia Ceramic Made of Baddeleyite

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4676
Author(s):  
Vyacheslav V. Rodaev ◽  
Andrey O. Zhigachev ◽  
Alexander I. Tyurin ◽  
Svetlana S. Razlivalova ◽  
Viktor V. Korenkov ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Phase Composition ◽  
Mechanical Characteristics ◽  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
High Energy ◽  
Zirconia Ceramic ◽  
Stabilized Zirconia ◽  
High Energy Milling ◽  
Polycrystalline Ceramic

Wet high-energy milling and uniaxial pressing are used to fabricate CaO-stabilized tetragonal zirconia polycrystalline ceramic (Ca-TZP) with decent mechanical characteristics, i.e., a hardness of 11.5 GPa, Young’s modulus of 230 GPa, and fracture toughness of 13 MPa·m0.5. The effect of CaO concentration and the sintering temperature on phase composition and mechanical characteristics of CaO-stabilized zirconia ceramic made of baddeleyite is investigated.

scholarly journals The Possible Detriment of Oxygen in Creep of Alumina and Zirconia Ceramic Composites Reinforced with Graphene

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 984
Author(s):  
Rafael Cano-Crespo ◽  
Pedro Rivero-Antúnez ◽  
Diego Gómez-García ◽  
Rodrigo Moreno ◽  
Arturo Domínguez-Rodríguez
Keyword(s):  
Graphene Oxide ◽  
High Temperature ◽  
Reduced Graphene Oxide ◽  
Tetragonal Zirconia ◽  
Careful Analysis ◽  
Ceramic Composites ◽  
Zirconia Ceramic ◽  
Creep Tests ◽  
Reduced Graphene ◽  
Average Grain Size

This paper is aims to give an answer to the following question: is the oxidation of graphene a critical issue for high-temperature plasticity in graphene-reinforced ceramics? To give a convincing reply, we will focus on two very different graphene-based ceramic composites: reduced graphene oxide (rGO)-reinforced alumina (α-Al2O3) and reduced graphene oxide (rGO)-reinforced yttria tetragonal zirconia (t-ZrO2). The processing of the powders has been made using a colloidal route, and after that, a spark plasma sintering process was performed in order to densify the samples. Creep tests were performed at temperatures between 1200–1250 °C in an argon atmosphere. The microstructure obtained by an SEM of the sintered and tested specimens was characterized quantitatively to elucidate the deformation mechanism. Raman spectroscopy was carried out to check the integrity of the graphene. The average grain size was in the order of 1 µm and the shape factor was 0.7 for all the studied materials. The integrity of the graphene was checked before and after the creep experiments. The careful analysis of the creep tests shows that graphene oxide or its reduced version are not efficient phases for creep resistance improvement in general, contrary to what is reported elsewhere. However, the results permit the suggestion of a creep improvement in nanocomposites at a very high temperature regime due to an enhanced reactivity of oxygen between carbon and alumina interfaces. In the case of zirconia, the results give us the conclusion that the oxidation of graphene is a highly detrimental issue regarding the improvement of high-temperature plasticity.

Effect of colourants on the optical characteristics and structure of Y 2 O 3 stabilised tetragonal zirconia ceramic

2021 ◽  
Author(s):  
Jianfeng Chen ◽  
Ning Wen ◽  
Chundong Xue ◽  
Zhaocen Liu ◽  
Zhuoran Liang ◽  
...  
Keyword(s):  
Tetragonal Zirconia ◽  
Optical Characteristics ◽  
Zirconia Ceramic

scholarly journals Mechanosynthesis and Thermoelectric Properties of Fe, Zn, and Cd-Doped P-Type Tetrahedrite: Cu12-xMxSb4S13

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3448
Author(s):  
Francisco Arturo López Cota ◽  
José Alonso Díaz-Guillén ◽  
Oscar Juan Dura ◽  
Marco Antonio López de la Torre ◽  
Joelis Rodríguez-Hernández ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Powder Processing ◽  
High Energy ◽  
Secondary Phases ◽  
Ambient Conditions ◽  
Cadmium Sulfate ◽  
Electrical Conductivities ◽  
Compositional Changes ◽  
P Type

This contribution deals with the mechanochemical synthesis, characterization, and thermoelectric properties of tetrahedrite-based materials, Cu12-xMxSb4S13 (M = Fe2+, Zn2+, Cd2+; x = 0, 1.5, 2). High-energy mechanical milling allows obtaining pristine and substituted tetrahedrites, after short milling under ambient conditions, of stoichiometric mixtures of the corresponding commercially available binary sulfides, i.e., Cu2S, CuS, Sb2S3, and MS (M = Fe2+, Zn2+, Cd2+). All the target materials but those containing Cd were obtained as single-phase products; some admixture of a hydrated cadmium sulfate was also identified by XRD as a by-product when synthesizing Cu10Cd2Sb4S13. The as-obtained products were thermally stable when firing in argon up to a temperature of 350–400 °C. Overall, the substitution of Cu(II) by Fe(II), Zn(II), or Cd(II) reduces tetrahedrites’ thermal and electrical conductivities but increases the Seebeck coefficient. Unfortunately, the values of the thermoelectric figure of merit obtained in this study are in general lower than those found in the literature for similar samples obtained by other powder processing methods; slight compositional changes, undetected secondary phases, and/or deficient sintering might account for some of these discrepancies.

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