Porous Alumina Ceramics with Multimodal Pore Size Distributions

Biggemann J, Stumpf M, Fey T (2021)


Publication Language: English

Publication Type: Journal article, Online publication

Publication year: 2021

Journal

Original Authors: Jonas Biggemann, Martin Stumpf, Tobias Fey

Book Volume: 14

Pages Range: 3294

Issue: 12

DOI: 10.3390/ma14123294

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 (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 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 (LFA) 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 (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.

Authors with CRIS profile

Additional Organisation(s)

How to cite

APA:

Biggemann, J., Stumpf, M., & Fey, T. (2021). Porous Alumina Ceramics with Multimodal Pore Size Distributions. Materials, 14, 3294. https://doi.org/10.3390/ma14123294

MLA:

Biggemann, Jonas, Martin Stumpf, and Tobias Fey. "Porous Alumina Ceramics with Multimodal Pore Size Distributions." Materials 14 (2021): 3294.

BibTeX: Download