authors |
Salomao, R; Kawamura, MA; Emilio, ABV; Sakihama, J; Segadaes, AM |
nationality |
International |
journal |
CERAMICS INTERNATIONAL |
author keywords |
Calcium hexaluminate; Alumina; Calcium aluminate cement; Porous ceramics |
keywords |
MICROSTRUCTURE DEVELOPMENT; MECHANICAL-PROPERTIES; THERMAL-CONDUCTIVITY; SETTING BEHAVIOR; TEMPERATURE; DEHYDRATION; FABRICATION; STABILITY; KINETICS |
abstract |
Calcium hexaluminate (CA6) is an intrinsically densification-resistant material, therefore, its porous structures are key materials for applications as high-temperature thermal insulators. This article reports on the combination of calcined alumina and calcium aluminate cement (CAC) in castable aqueous suspensions for the in situ production of porous CA6. The CAC content (10?34 vol%) and the curing conditions ensure structural integrity prior to sintering and maximize the development of hydrated phases. Changes in physical properties, crystalline phases, and microstructure were investigated after isothermal treatments (120?1500 ?C), and three sequential porogenic events were observed. The hydration of CAC preserved the water-derived pores (up to 120 ?C), and the dehydroxylation of CAC hydrates (250?700 ?C) generated inter-particles pores. Moreover, the in situ expansive formation of CA2 and CA6 (900?1500 ?C) hindered densification and generated intra-particle pores. Such events differed from those observed with other CaO sources, and resulted in significantly higher pores content and lower thermal conductivity. |
publisher |
ELSEVIER SCI LTD |
issn |
0272-8842 |
isbn |
1873-3956 |
year published |
2021 |
volume |
47 |
issue |
11 |
beginning page |
15082 |
ending page |
15093 |
digital object identifier (doi) |
10.1016/j.ceramint.2021.02.066 |
web of science category |
12 |
subject category |
Materials Science, Ceramics |
unique article identifier |
WOS:000640984300007
|
ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
3.83 |
5 year journal impact factor |
3.513 |
category normalized journal impact factor percentile |
94.643 |
dimensions (citation analysis):
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altmetrics (social interaction):
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