Porous Alumina Ceramics with Multimodal Pore Size Distributions
Pore networks with multimodal pore size distributions combining advantages from isotropic and anisotropic shaped pores of different sizes are highly attractive to optimize the physical properties of porous ceramics. Multimodal porous Al<sub>2</sub>O<sub>3</sub> ceramics were...
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MDPI AG
2021-06-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/12/3294 |
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| author | Jonas Biggemann Martin Stumpf Tobias Fey |
| author_facet | Jonas Biggemann Martin Stumpf Tobias Fey |
| author_sort | Jonas Biggemann |
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| description | Pore networks with multimodal pore size distributions combining advantages from isotropic and anisotropic shaped pores of different sizes are highly attractive to optimize the physical properties of porous ceramics. Multimodal porous Al<sub>2</sub>O<sub>3</sub> ceramics were manufactured using pyrolyzed cellulose fibers (l = 150 µm, d = 8 µm) and two types of isotropic phenolic resin spheres (d = 30 and 300 µm) as sacrificial templates. The sacrificial templates were homogeneously distributed in the Al<sub>2</sub>O<sub>3</sub> matrix, compacted by uniaxial pressing and extracted by a burnout and sintering process up to 1700 °C in air. The amount of sacrificial templates was varied up to a volume content of 67 Vol% to form pore networks with porosities of 0–60 Vol%. The mechanical and thermal properties were measured by 4-point-bending and laser flash analysis (LFA) resulting in bending strengths of 173 MPa to 14 MPa and heat conductivities of 22.5 Wm<sup>−1</sup>K<sup>−1</sup> to 4.6 Wm<sup>−1</sup>K<sup>−1</sup>. Based on µCT-measurements, the representative volume-of-interest (VOI) of the samples digital twin was determined for further analysis. The interconnectivity, tortuosity, permeability, the local and global stress distribution as well as strut and cell size distribution were evaluated on the digital twin’s VOI. Based on the experimental and simulation results, the samples pore network can be tailored by changing the fiber to sphere ratio and the overall sacrificial template volume. The presence pore formers significantly influenced the mechanical and thermal properties, resulting in higher strengths for samples containing fibrous templates and lower heat conductivities for samples containing spherical templates. |
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| spelling | doaj.art-249d8eecef9840c8a22f9336b2fce0bf2023-11-22T00:05:39ZengMDPI AGMaterials1996-19442021-06-011412329410.3390/ma14123294Porous Alumina Ceramics with Multimodal Pore Size DistributionsJonas Biggemann0Martin Stumpf1Tobias Fey2Department of Materials Science (Glass and Ceramics), University of Erlangen-Nuernberg, Martensstr. 5, D-91058 Erlangen, GermanyDepartment of Materials Science (Glass and Ceramics), University of Erlangen-Nuernberg, Martensstr. 5, D-91058 Erlangen, GermanyDepartment of Materials Science (Glass and Ceramics), University of Erlangen-Nuernberg, Martensstr. 5, D-91058 Erlangen, GermanyPore networks with multimodal pore size distributions combining advantages from isotropic and anisotropic shaped pores of different sizes are highly attractive to optimize the physical properties of porous ceramics. Multimodal porous Al<sub>2</sub>O<sub>3</sub> ceramics were manufactured using pyrolyzed cellulose fibers (l = 150 µm, d = 8 µm) and two types of isotropic phenolic resin spheres (d = 30 and 300 µm) as sacrificial templates. The sacrificial templates were homogeneously distributed in the Al<sub>2</sub>O<sub>3</sub> matrix, compacted by uniaxial pressing and extracted by a burnout and sintering process up to 1700 °C in air. The amount of sacrificial templates was varied up to a volume content of 67 Vol% to form pore networks with porosities of 0–60 Vol%. The mechanical and thermal properties were measured by 4-point-bending and laser flash analysis (LFA) resulting in bending strengths of 173 MPa to 14 MPa and heat conductivities of 22.5 Wm<sup>−1</sup>K<sup>−1</sup> to 4.6 Wm<sup>−1</sup>K<sup>−1</sup>. Based on µCT-measurements, the representative volume-of-interest (VOI) of the samples digital twin was determined for further analysis. The interconnectivity, tortuosity, permeability, the local and global stress distribution as well as strut and cell size distribution were evaluated on the digital twin’s VOI. Based on the experimental and simulation results, the samples pore network can be tailored by changing the fiber to sphere ratio and the overall sacrificial template volume. The presence pore formers significantly influenced the mechanical and thermal properties, resulting in higher strengths for samples containing fibrous templates and lower heat conductivities for samples containing spherical templates.https://www.mdpi.com/1996-1944/14/12/3294digital-twinvolume-of-interesthierarchical networksacrificial templatemultimodal pore size distribution |
| spellingShingle | Jonas Biggemann Martin Stumpf Tobias Fey Porous Alumina Ceramics with Multimodal Pore Size Distributions Materials digital-twin volume-of-interest hierarchical network sacrificial template multimodal pore size distribution |
| title | Porous Alumina Ceramics with Multimodal Pore Size Distributions |
| title_full | Porous Alumina Ceramics with Multimodal Pore Size Distributions |
| title_fullStr | Porous Alumina Ceramics with Multimodal Pore Size Distributions |
| title_full_unstemmed | Porous Alumina Ceramics with Multimodal Pore Size Distributions |
| title_short | Porous Alumina Ceramics with Multimodal Pore Size Distributions |
| title_sort | porous alumina ceramics with multimodal pore size distributions |
| topic | digital-twin volume-of-interest hierarchical network sacrificial template multimodal pore size distribution |
| url | https://www.mdpi.com/1996-1944/14/12/3294 |
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