scholarly journals Enhancing Compressive Strength of Reticulated Porous Alumina by Optimizing Processing Conditions

2021 ◽  
Vol 11 (10) ◽  
pp. 4517
Author(s):  
Sujin Lee ◽  
Chae Young Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Porous Alumina ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Solid Loading ◽  
Average Particle ◽  
High Porosity ◽  
Processing Conditions ◽  
Mechanical Instability ◽  
Porosity And Permeability

Recently, porous ceramics have received much attention from researchers because of their excellent thermal and chemical stabilities compared to their counterparts (such as porous polymers and metals), despite their inferior mechanical instability. Among the various types of porous ceramics, reticulated porous ceramics have significant industrial potential because of their synergistic high porosity and permeability. However, to the best of our knowledge, there is insufficient data on the processing conditions or preparing optimal reticulated porous alumina. Therefore, we prepared and characterized reticulated porous alumina specimens by controlling various processing conditions, namely average particle size, solid loading, binder, and dispersant. The data obtained were used to assess whether the compressive strength of the reticulated porous alumina could be enhanced and to discuss the potential of these materials for various applications.

scholarly journals Effect of Processing Conditions on the Properties of Reticulated Porous Diatomite–Kaolin Composites

2020 ◽  
Vol 10 (20) ◽  
pp. 7297
Author(s):  
Sujin Lee ◽  
Chae Young Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Porous Ceramic ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Solid Loading ◽  
Natural Material ◽  
Average Particle ◽  
High Porosity ◽  
Processing Conditions ◽  
Porous Metals ◽  
Mechanical Instability

Porous ceramics have been extensively investigated because of their high-temperature and chemical stabilities, which are far superior to those of porous polymers and porous metals, despite their mechanical instability. Among various kinds of porous ceramic, reticulated porous ceramics have attracted considerable attention because of their extremely high porosity, which is generally higher than 90% and can maximize the advantages of this class of materials. However, to the best of our knowledge, sufficient data are not available on the preparation of low-cost, abundant, and natural material-based reticulated porous ceramics. Therefore, we obtained and characterized reticulated porous diatomite–kaolin composites prepared under various processing conditions, such as solid loading, average particle size, and pore density. The experimental data were used to investigate whether the densities and compressive strengths of the reticulated porous diatomite–kaolin composite can be tailored, and to assess the potential of these materials in different application fields.

scholarly journals The Effects of a Zirconia Addition on the Compressive Strength of Reticulated Porous Zirconia-Toughened Alumina

2021 ◽  
Vol 11 (19) ◽  
pp. 9326
Author(s):  
Chae-Young Lee ◽  
Sujin Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Solid Loading ◽  
Average Particle ◽  
High Porosity ◽  
Processing Conditions ◽  
Porous Metals ◽  
Porous Zirconia ◽  
Zirconia Toughened Alumina

Porous ceramics have attracted researchers due to their high chemical and thermal stability. Among various types of porous ceramics, reticulated porous ceramics have both high porosity and good permeability. These properties of porous ceramics are difficult to replace with porous metals and polymers. ZTA is used in a variety of applications, and a wealth of experimental data has already been collected. However, research reports on reticulated porous zirconia-toughened alumina (ZTA) are insufficient. Therefore, we prepared reticulated porous ZTA via the replica template method. In this study, various processing conditions (average particle size, zirconia content, solid loading, dispersant, and thickener) were adjusted to improve the compressive strength of the reticulated porous ZTA. As a result, the optimized processing conditions for improving the compressive strength of reticulated porous ZTA could be determined.

scholarly journals Effect of the Sintering Temperature on the Compressive Strengths of Reticulated Porous Zirconia

2021 ◽  
Vol 11 (12) ◽  
pp. 5672
Author(s):  
Chae-Young Lee ◽  
Sujin Lee ◽  
Jang-Hoon Ha ◽  
Jongman Lee ◽  
In-Hyuck Song ◽  
...  
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Porous Ceramic ◽  
Average Particle Size ◽  
Porous Ceramics ◽  
Average Particle ◽  
High Porosity ◽  
Wide Range ◽  
Porous Zirconia

Porous ceramics have separation/collection (open pore) and heat-shielding/sound-absorbing (closed pore) characteristics not found in conventional dense ceramics, increasing their industrial importance along with dense ceramics. Reticulated porous ceramics, a type of porous ceramic material, are characterized by a three-dimensional network structure having high porosity and permeability. Although there have been numerous studies of porous zirconia, which is already widely used, there are insufficient reports on reticulated porous zirconia, and it is still challenging to improve the compressive strength of reticulated porous ceramics thus far, especially considering that too few studies have been published on this topic. Therefore, we prepared reticulated porous zirconia specimens using the replica template method. In this study, the compressive strength outcomes of reticulated porous zirconia were analyzed by controlling the PPI value (25, 45, 60, and 80 PPI) of the sacrificial polymer template, the average zirconia particle size (as-received, coarse, intermediate, and fine), and the sintering temperature (1400, 1500, and 1600 °C). Consequently, we confirm that it is possible to prepare reticulated porous zirconia with a wide range of strengths (0.16~1.26 MPa) as needed with an average particle size and while properly controlling the sintering temperature.

Fabrication and Microstructure of ZnO-TiO2 Composite Membranes by a Reverse Micelle and Sol-Gel Processing

2006 ◽  
Vol 510-511 ◽  
pp. 786-789 ◽  
Author(s):  
Dong Sik Bae ◽  
Byung Ik Kim ◽  
Kyong Sop Han
Keyword(s):  
Particle Size ◽  
Reverse Micelle ◽  
Porous Alumina ◽  
Sol Gel ◽  
Average Particle Size ◽  
Composite Membranes ◽  
Dip Coating ◽  
Narrow Particle Size Distribution ◽  
Average Particle ◽  
Alumina Support

ZnO-TiO2 nanoparticles were synthesized by a reverse micelle and sol-gel process. The average particle size of the colloid was below 30 nm and well dispersed in the solution. ZnOTiO2 composite membranes were fabricated by using the dip-coating method on a porous alumina support. ZnO-TiO2 composite membranes showed a crack-free microstructure and narrow particle size distribution even after the heat treatment up to 600°C. The average particle size of the membrane was 30-40nm, and the pore size of ZnO-TiO2 composite membrane was below 10 nm.

Characteristics of High Content Steel Briquettes Using Nanosized Solid Binders

2021 ◽  
Vol 21 (7) ◽  
pp. 3863-3867
Author(s):  
Seung-Ju Lim ◽  
Seong-Gyu Seo ◽  
Hyung-Sun Yoon
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Average Particle Size ◽  
Average Particle ◽  
Eds Analysis

In this study, we investigated the characteristics of high-content steel briquettes produced using various nanoscale solid binders and steel byproducts (SS, SCS, SLD, and BSD). The average particle size was 0.171 nm for S5, 0.065 nm for S1, 0.058 nm for S4, and 0.040 nm for S2 and S3. The SEM-EDS analysis of the solid power binder resulted in mostly rectangular images. The compressive strength of the high-content steel briquettes was 120 kgf/cm2, with the highest HSL1 using S4 binders. The compressive strength of the high-content steel briquettes was in the order of HSS4 > HSS1 > HSS3 > HSS5 > HSS2.

Structural, Microscopy Analysis and Compressive Strength of ZnO–CuO Nanocomposites

2020 ◽  
Vol 12 (2) ◽  
pp. 163-167
Author(s):  
K. Kavitha ◽  
T. Subba Rao ◽  
R. Padma Suvarna ◽  
M. Prasanna Kumar
Keyword(s):  
Compressive Strength ◽  
Sol Gel ◽  
Average Particle Size ◽  
Testing Machine ◽  
Research Area ◽  
Strength Analysis ◽  
Average Particle ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Active Research

Currently, researches on nanocomposites become an active research area due its unique properties. Earlier, many researches are done for synthesizing the multidimensional structures for developing efficient and new Nano devices. In this present work, we synthesized ZnO–CuO nanocomposites using sol–gel method. The obtained nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) analysis and Compressive strength analysis using compressive testing machine (CTM). Herein, the structure and size of the ZnO–CuO nanocomposites were studied using XRD. And the average particle size was found to be 34 nm. The TEM analysis has the evidence of the XRD result. The enhancement in compressive strength of the ZnO–CuO nanocomposites was determined using CTM machine up to 4 wt.%.

Thermal Conductivity of Porous Alumina-Zirconia Prepared by Foam Technique for Applications in Cooling Systems of Artificial Satellites

2010 ◽  
Vol 636-637 ◽  
pp. 161-167 ◽  
Author(s):  
Ana Coh O. Hirschmann ◽  
Maria do Carmo de Andrade Nono ◽  
Cosme Roberto Moreira Silva
Keyword(s):  
Thermal Conductivity ◽  
Porous Alumina ◽  
Mercury Porosimetry ◽  
Tetragonal Zirconia ◽  
Porous Ceramics ◽  
Zirconia Ceramic ◽  
Artificial Satellites ◽  
High Porosity ◽  
Cooling Systems ◽  
Loop Heat Pipes

Porous ceramics are of great interest due to their numerous potential applications. The objective of the present investigation was to produce porous alumina with 3 mol % yttria-stabilized tetragonal zirconia (Y-TZP). This material will be used in cooling systems of satellites. To obtain the porous ceramics the direct foaming technique was used. This method is based on the preparation of a stable foam to which a slurry of alumina and zirconia is added. The mixture is then vigorously stirred for incorporation of air. The sintered ceramics were characterized by scanning electron microscopy, mercury porosimetry and thermal conductivity. The tests performed with the porous alumina-zirconia ceramic composite obtained by this method, showed low thermal conductivity values, high porosity and uniform microstructure with 20–100 µm open pores. The results show that the alumina-zirconia composites tested in this study have a potential for application in loop heat pipes of cooling systems of satellites.

scholarly journals Alumina Porous Ceramics Obtained by Freeze Casting: Structure and Mechanical Behaviour under Compression

Ceramics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Dominique Hautcoeur ◽  
Maurice Gonon ◽  
Carmen Baudin ◽  
Véronique Lardot ◽  
Anne Leriche ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Mechanical Behaviour ◽  
Volume Fraction ◽  
Mechanical Test ◽  
Porous Alumina ◽  
Microstructural Analysis ◽  
Porous Ceramics ◽  
Sem Analysis ◽  
Deformation Pattern ◽  
Freeze Casting

The aim of the work is to analyse the mechanical behaviour of anisotropic porous alumina ceramics processed by freeze casting (ice templating). The freeze cast specimens were characterised by a lamellar structure with ellipsoidal pore shape, with a size ranging from 6 to 42 µm and 13 to 300 µm for the minor and major axes, respectively, as a function of the freezing rate and the powder and binder contents. The pore volume fraction ranged from 40 to 57%. SEM analysis of the porous structures after the compression test showed a typical deformation pattern caused by the porosity gradient through the specimen, as determined by X-ray radiography. The apparent elastic modulus of the anisotropic porous alumina ranged from 0.2 to 14 GPa and the compressive strength from 6 to 111 MPa, varying as a function of the process parameters which determine the pore network characteristics. The relationships between stress-strain behaviour in compression and the microstructure and texture were established. An analytical model based on a Gibson and Ashby relationship was used and adapted from SEM microstructural analysis after a mechanical test in order to predict the compressive strength of processed anisotropic alumina.

Porous Alumina-Zirconia Prepared by Foam Technique for Applications as Cooling Systems of Artificial Satellites

2008 ◽  
Vol 591-593 ◽  
pp. 865-869
Author(s):  
Ana Coh O. Hirschmann ◽  
Maria do Carmo de Andrade Nono ◽  
R.R. Riehl ◽  
Cosme Roberto Moreira Silva
Keyword(s):  
Porous Alumina ◽  
Mercury Porosimetry ◽  
Heat Pipes ◽  
Porous Ceramics ◽  
Industrial Applications ◽  
Artificial Satellites ◽  
High Porosity ◽  
Cooling Systems ◽  
Uniform Microstructure ◽  
New Applications

The interest in porous ceramics has increased concurrently with new processes and new applications. This material has been used in several industrial applications such as filters, catalysis and sensors. The objective of the present investigation was to produce porous alumina with 3 % mol yttria stabilized zirconia in tetragonal crystalline structure (Y-TZP). This material will be used in cooling systems of satellites, due to its mechanical properties and chemical inertia. To obtain the porous ceramics was used the direct foaming technique, which is a method based on the preparation of a stable foam slurry and a slurry of alumina and zirconia that are later mixed and blended for incorporation of air in the mixture. The sintered ceramics was characterized by scanning electronic microscopy, mercury porosimetry and permeability measurements. The porous Al2O3–ZrO2 ceramics obtained showed high porosity and uniform microstructure with 20–100 ,m open pores. The results from these alumina zirconia composites showed a potential to apply in heat pipes.

Fabrication, Structure and Properties of Porous SiC Ceramics with High Porosity and High Strength

2010 ◽  
Vol 105-106 ◽  
pp. 608-611 ◽  
Author(s):  
Shao Feng Wang ◽  
Chang An Wang ◽  
Jia Lin Sun ◽  
Li Zhong Zhou ◽  
Yong Huang
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Butyl Alcohol ◽  
Solid Loading ◽  
High Porosity ◽  
Reaction Bonding ◽  
Sintering Additive ◽  
Sic Ceramics ◽  
Tert Butyl Alcohol ◽  
Porous Sic

Porous SiC ceramics with high porosity and high strength were fabricated by gelcasting, with tert-butyl alcohol (TBA) as solvent, acrylamide (AM) as monomer, and in-situ reaction bonding with a-Al2O3 as sintering additive. SiC suspension with 10 vol% solid loading was successfully solidified by gel-casting to form high strength green body. The results showed that the compressive strength of the porous SiC ceramics increased with sintering temperature from 1300 to 1450°C, but porosity had little change, due to formation of more volume of cristobalite and mullite phases on the surface of SiC grains, accompanied by a large volume expansion effect. Very narrow single-peak distributions with about 2 mm median pore diameter could be found for the porous SiC ceramics. The porosity and compressive strength of the porous SiC ceramics sintered at 1450°C were 71.21 % and 12.14 MPa, respectively.

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