Microstructure and elastic properties of highly porous mullite ceramics prepared with wheat flour
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F16%3A43902681" target="_blank" >RIV/60461373:22310/16:43902681 - isvavai.cz</a>
Result on the web
—
DOI - Digital Object Identifier
—
Alternative languages
Result language
angličtina
Original language name
Microstructure and elastic properties of highly porous mullite ceramics prepared with wheat flour
Original language description
Porous mullite-based foams prepared by direct foaming with wheat flour and partial sintering at 1600 oC have been characterized via optical and electron microscopy, stereology- based image analysis, mercury porosimetry and impulse excitation. By varying the time of homogenization in a shaker from 0.1 to 10 h the porosity of the mullite foams could be varied in the range 49-88 % and the mean foam cell size in the range 105-320 ?m. Microscopic investigation and mercury porosimetry confirmed that the pore space is essentially open (interconnected) and revealed the hierarchical microstructure of the materials, consisting of large foam cells, intermediate convex pores from wheat starch burnout and small concave pores between the partially sintered ceramic particles, on all levels interconneted by cell windows or throats that are significantly smaller than the foam cells and pore cavities. Elastic properties have been determined with specimens in the form of thin circular disks, using the resonant frequencies of flexural and anti-flexural vibrations. It has been found that for samples with porosities of 78 % and higher the Young's modulus and shear modulus are very close to the power-law prediction (Gibson-Ashby relation for open-cell foams), whereas for smaller porosities the values are much lower and for porosities of 48 % even lower than our exponential relation, which indicates the dominating effect of concave pores (due to partial sintering of convex particles). Poisson ratios are close to the value 0.2 and reasonably well predicted by the linear approximation.
Czech name
—
Czech description
—
Classification
Type
D - Article in proceedings
CEP classification
JH - Ceramics, fire-proof materials and glass
OECD FORD branch
—
Result continuities
Project
<a href="/en/project/GA15-18513S" target="_blank" >GA15-18513S: Processing and characterization of oxide and silicate ceramics with controlled microstructure and modeling of microstructure-property relations</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Article name in the collection
11th International Symposium on Ceramic Materials and Components for Energy and Environmental Applications
ISBN
978-1-119-23458-6
ISSN
1042-1122
e-ISSN
—
Number of pages
12
Pages from-to
83-94
Publisher name
American Ceramic Society (ACerS)
Place of publication
Westerville, Ohio
Event location
Vancouver / Canada
Event date
Jun 14, 2015
Type of event by nationality
WRD - Celosvětová akce
UT code for WoS article
—