Page 30 - ILK Research Report 2020

Gescha

Development of the principles of foam structure formation
in the freeze-foaming process of biocompatible ceramic foams

Freeze foams are novel and innovative cellular structures based on a direct Period
foaming process, which can be generated from any material that can be pro- 01.01.2020 – 31.12.2021
cessed by powder technology. The foam production process is influenced by
a complex interaction of a wide variety of process and material parameters, Project Director
which were previously selected empirically and were difficult to reproduce. Prof. Dr.-Ing. habil. Maik Gude
For specific property design, there is a need to investigate phenomena occur-
ring during foam formation and the effect of relevant process and material Contact Person
parameters in order to develop manufacturing principles. The possible ap- Johanna Maier
plications of such foam structures cover a very diverse spectrum and range Tobias Kastner
from biomedical applications to supports for catalysts. The diversity of these
applications results from the range of starting suspensions and from the pro- Funding
cess parameter-dependent foam structure properties, such as cell geometry, German Research Foundation (DFG)
cell size distribution and the nature of the cell webs. In the first project phase,
a deeper understanding of freeze foam structure formation was achieved by Project Partner
performing analyses on the influence of selected suspension and process Fraunhofer-Institut für Keramische
parameters on relevant structural properties. On the basis of the knowledge Technologien und Systeme (IKTS)
gained, the focus of current research is on the targeted tailoring of the mac-
rostructure and microstructure to produce ceramic foams that are suitable
for specific stresses and applications.

foam cells

e: 30 mbar; d: 40 mbar;
filled webs with P = 64,6 % P = 50,8 % c: 50 mbar;
micropores 400 µm P = 41,7 %
2500
2500
2000
2000
3D printed ceramic 1500 b)
absolute frequency 1000 a) c) b: 70 mbar;
1500
1000
P = 26,8 %
500
500
d)
e)
0 0
Freeze Foam 1,00E+06 1,00E+07 1,00E+08 1,00E+09 1,00E+10 1,00E+11 1,00E+12
e 9
e 10
e 12
µm 3
e 7
e 6
e 8
pore volume
P…porosity pore volume
source: IKTS a: 100 mbar;
P = 4,6 %
Pore size distribution during the foaming process at different pressure levels
Funded by
German Research Foundation

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