Porous ceramic foams are used in a wide field of applications as catalyst support structures, lightweight materials, filtration, energy or acoustic adsorption or energy storage materials. Beside this, porous ceramic scaffold for bone replacement are a promising material in future to ensure a faster medical healing.
In addition to determining the pore morphology, surface, connectivity and shape, the physical properties (thermal, mechanical, acoustic) are of crucial relevance for the applications mentioned. There is a difference here compared to dense ceramic materials, as the structural as well as physical properties are significantly shaped via the pores and porosity. Therefore, it is essential to determine the minimum volume, which allows a generally valid prediction for the entire structure. This so-called representative volume-of-interest (REVOI) can be determined by a combination of image evaluation based on µCT images and FE simulations in combination with physical measurements. Using examples of Al2O3 replica foams [1], porous Al2O3 ceramics via sacrificial templates [2] and 3D printed structures [3], the principle and necessity of the representative volume is explained.

[1] Fey, T., Determination of the representative Volume-of-interest (REVOI) in ceramic replica foams, Open Ceramics (2021), 7, 100154, 10.1016/j.oceram.2021.100154
[2] Biggemann, J., Stumpf, M., Fey, T., Porous alumina ceramics with multimodal pore size distributions, Materials (2021), 14, 3294, 10.3390/ma14123294
[3] Biggemann J., Köllner, D., Schatz, J., Stumpf M., Fey, T., Influence of µCT scanning resolution and volume on FEM-simulation of periodic 3D-printed porous ceramics, Materials Letters (2021), 303, 130529, 10.1016/j.matlet.2021.130529