Dr. Tobias Fey at the 46th International Conference and Expo on Advanced Ceramics and Composites
In his talk about ‚Porous Alumina Ceramics with Multimodal Pore Size Distributions‘ he discussed his research group’s previous paper.
Abstract: 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 Al2O3 ceramics were manufactured using pyrolyzed cellulose fibers and two types of isotropic phenolic resin spheres as sacrificial templates. The sacrificial templates were homogeneously distributed in the Al2O3 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 resulting in bending strengths of 173 MPa to 14 MPa and heat conductivities of 22.5 Wm−1K−1 to 4.6 Wm−1K−1.
Based on μCT-measurements, the representative volume-of-interest of the samples digital twin was determined for further analysis. The interconnectivity, tortuosity, permeability, stress distribution as well as strut and cell size distribution were evaluated on the digital twin’s VOI. 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.
Jonas Biggemann, Tobias Fey, Martin Stumpf: Porous Alumina Ceramics with Multimodal Pore Size Distributions, Materials 2021, 14(12), 3294