scholarly journals Preparation of Porous Alumina/Nano-Nickel Composite by Gel Casting and Carbothermic Reduction

2022 ◽  
Vol 35 (1) ◽  
Keyword(s):  
Carbothermic Reduction ◽  
Porous Alumina ◽  
Gel Casting ◽  
Nano Nickel

Fabrication of porous alumina–zirconia ceramics by gel-casting and infiltration methods

2014 ◽  
Vol 63 ◽  
pp. 1-5 ◽  
Author(s):  
Ruiping Liu ◽  
Yutao Li ◽  
Chang-An Wang ◽  
Shengnian Tie
Keyword(s):  
Porous Alumina ◽  
Zirconia Ceramics ◽  
Gel Casting

High-strength macro-porous alumina ceramics with regularly arranged pores produced by gel-casting and sacrificial template methods

2019 ◽  
Vol 54 (14) ◽  
pp. 10119-10129 ◽  
Author(s):  
Mengwen Zhang ◽  
Xiaodong Li ◽  
Mu Zhang ◽  
Zhimeng Xiu ◽  
Ji-Guang Li ◽  
...  
Keyword(s):  
Porous Alumina ◽  
High Strength ◽  
Alumina Ceramics ◽  
Sacrificial Template ◽  
Gel Casting ◽  
Template Methods

Optimized processing of defect-free porous alumina by gel casting process

2018 ◽  
Vol 26 (3) ◽  
pp. 619-630 ◽  
Author(s):  
Devavarapu Soumya ◽  
Santanu Bhattacharyya
Keyword(s):  
Porous Alumina ◽  
Casting Process ◽  
Gel Casting

Fabrication and Characteristic of Porous Alumina Developed with SiC Nano-Fiber or Nano-Whisker

2006 ◽  
Vol 317-318 ◽  
pp. 693-696
Author(s):  
Sung Jae Je ◽  
Jae Won Kim ◽  
Yeon Gil Jung ◽  
Ung Yu Paik
Keyword(s):  
Porous Alumina ◽  
Volume Ratio ◽  
Liquid Droplets ◽  
Carbon Particles ◽  
Sic Fiber ◽  
Gel Casting ◽  
Nano Fiber ◽  
Formation Behavior ◽  
Mercury Porosimeter ◽  
Pmma Beads

Porous alumina green bodies were fabricated by a gel-casting method, for which the slurries of alumina (AKP-30) and PMMA (polymethylmetacrylate) bead were mixed and dispersed at 1:1, 1:2, 1:3, and 1:4 volume ratios. PMMA bead as precursor of carbon source was used for growing SiC nano-fiber or nano-whisker during a VLS (vapor-liquid-solid) reaction at 1450°C for 9hrs. PMMA beads are converted to carbon particles after calcination at 1300°C for 9hrs in static argon (Ar) atmosphere. Finally, carbon particles remain in pores of alumina bodies connected by continuous pore channels. Fe solution was infiltrated into the porous alumina bodies, which are absorbed on the carbon particles in pores. Fe precursor functions as a seed to develop the SiC nano-fiber or nano-whisker in the porous alumina bodies. The liquid droplets formed at the end of the SiC fiber or whisker are evident for the typical VLS mechanism. The microstructure of the SiC fiber or whisker grown by the VLS reaction was observed by SEM. The porosity was measured by mercury porosimeter. The formation behavior of SiC fiber or whisker is dependent on volume ratio of carbon converted from PMMA bead.

Evaluation and Control of Crack Propagation in Dense Porcelain/ Porous Alumina Layered Structures for Dental Material Applications

2006 ◽  
Vol 317-318 ◽  
pp. 457-460 ◽  
Author(s):  
Jae Won Kim ◽  
Seong Hwan Park ◽  
Yeon Gil Jung ◽  
Hee Soo Lee
Keyword(s):  
Crack Propagation ◽  
Buffer Layer ◽  
Porous Alumina ◽  
Casting Process ◽  
Layered Structures ◽  
Alumina Powder ◽  
High Porosity ◽  
Gel Casting ◽  
And Control ◽  
Layered Samples

Layered structures of dense porcelain/porous alumina and dense porcelain/porcelainalumina/ porous alumina are designed and their crack propagation behaviors are investigated. As a substrate, the porous alumina, which is prepared by a gel-casting process using the binary slip of alumina powder and PMMA spherical micro-bead, is dried at room temperature for 24 h and then sintered at 1600 for 2 h. Porcelain is coated on the porous alumina substrate and then re-sintered at 987. Bi- and tri-layered structures are produced by the different dwell times (2 min, 10 min) at re-sintering temperature. There is no delaminating or cracks observed after re-sintering the layered samples. The crack propagation behaviors in the bi- and tri-layered structures are evaluated by micro-indentation. The indentation cracks do not propagate into the porous alumina through interface (porosity; 36~62%) except for another one (porosity; 70%) in the bi-layered samples. In the case of the high porosity bi-layered sample (porosity; 70%), cracks are scattered along the 3-D open-pore channels. However, cracks do not propagate through the interface in the tri-layered samples with a porcelain-alumina buffer layer, because the porcelain-alumina buffer layer plays an important part such as a barrier layer in crack propagation.

Porous Alumina and Zirconia Bodies Obtained by a Novel Gel Casting Process

2009 ◽  
pp. 327-338
Author(s):  
Jean-Marc Tulliani ◽  
Valentina Naglieri ◽  
Mariangela Lombardi ◽  
Laura Montanaro
Keyword(s):  
Porous Alumina ◽  
Casting Process ◽  
Gel Casting

scholarly journals Processing of Macroporous Alumina Ceramics Using Pre-Expanded Polymer Microspheres as Sacrificial Template

Ceramics ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Marina Ciurans Oset ◽  
Jan Nordin ◽  
Farid Akhtar
Keyword(s):  
Size Distribution ◽  
Porous Alumina ◽  
Total Porosity ◽  
Porous Ceramics ◽  
Industrial Applications ◽  
High Porosity ◽  
Polymeric Microspheres ◽  
Gel Casting ◽  
Microscopy Investigation ◽  
Reliable Model

Shaped porous ceramics have proven to be the most adapted materials for several industrial applications, both at low and high temperatures. Recent research has been focused on developing shaping techniques, allowing for a better control over the total porosity and the pores characteristics. In this study, macroporous alumina foams were fabricated by gel-casting using pre-expanded polymeric microspheres with average sizes of 40 μm, 20 μm, and 12 μm as sacrificial templates. The gel-casting method, as well as the drying, debinding, and presintering conditions were investigated and optimized to process mechanically strong and highly porous alumina scaffolds. Furthermore, a reliable model relating the amount of pre-expanded polymeric microspheres and the total porosity of the presintered foams was developed and validated by mercury intrusion porosimetry measurements. The electron microscopy investigation of the presintered foams revealed that the size distribution and the shape of the pores could be tailored by controlling the particle size distribution and the shape of the wet pre-expanded microspheres. Highly uniform and mechanically stable alumina foams with bimodal porosity ranging from 65.7 to 80.2 vol. % were processed, achieving compressive strengths from 3.3 MPa to 43.6 MPa. Given the relatively open pore structure, the pore size distribution, the presintered mechanical strength, and the high porosity achieved, the produced alumina foams could potentially be used as support structures for separation, catalytic, and filtration applications.

Sign in / Sign up

Export Citation Format

Share Document