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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Preparation and Characterization of Mullite-Alumina Structures Formed ``In Situ{''} from Calcined Alumina and Different Grades of Synthetic Amorphous Silica

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Author(s):
Fernandes, Leandro [1] ; Salomao, Rafael [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Engn Mat, Ave Trabalhador Sao Carlense 400, Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 21, n. 3 2018.
Web of Science Citations: 2
Abstract

The in situ reaction between alumina and silica to obtain mullite (Al6Si4O13) can be significantly affected by using synthetic amorphous silica (SAS) sources instead of crystalline ones (quartz and cristobalite). For instance, SASs promote early mullite formation (below 1300 degrees C) and greater densification during sintering. This paper reports the ``in situ{''} formation of mullite-alumina structures from fine calcined alumina (alpha-Al2O3) and four grades of SAS of different particles' morphology, specific surface area and internal porosity. After sintering assisted by dilatometry (up to 1500 degrees C), the samples' total porosity, density and flexural strength were measured. The relative density and strength levels of some of these structures were greater than or comparable to other studies in which similar compositions were sintered at higher temperatures (1600-1700 degrees C). Their microstructure assessment indicated that the specific surface area and internal porosity of SAS particles showed a major influence in the development of these physical properties. (AU)

FAPESP's process: 10/19274-5 - Novel methodology for hydrotalcite (Mg6Al2(OH)16CO3.4H2O) synthesis from aqueous suspensions of magnesium oxide (MgO) and aluminum hydroxide (Al(OH)3) and its application in porous ceramics for high temperature thermal insulation
Grantee:Rafael Salomão
Support type: Research Grants - Young Investigators Grants