Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica
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°C) and greater densifica...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
2018-03-01
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| Series: | Materials Research |
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| Online Access: | http://www.scielo.br/pdf/mr/v21n3/1516-1439-mr-1980-5373-MR-2017-0783.pdf |
| _version_ | 1819008198457163776 |
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| author | Leandro Fernandes Rafael Salomão |
| author_facet | Leandro Fernandes Rafael Salomão |
| author_sort | Leandro Fernandes |
| collection | DOAJ |
| description | 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°C) and greater densification during sintering. This paper reports the "in situ" formation of mullite-alumina structures from fine calcined alumina (α-Al2O3) and four grades of SAS of different particles' morphology, specific surface area and internal porosity. After sintering assisted by dilatometry (up to 1500°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°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. |
| first_indexed | 2024-12-21T00:36:40Z |
| format | Article |
| id | doaj.art-5ea42fe47b904ba09064679bc4192c98 |
| institution | Directory Open Access Journal |
| issn | 1516-1439 |
| language | English |
| last_indexed | 2024-12-21T00:36:40Z |
| publishDate | 2018-03-01 |
| publisher | Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) |
| record_format | Article |
| series | Materials Research |
| spelling | doaj.art-5ea42fe47b904ba09064679bc4192c982022-12-21T19:21:47ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392018-03-0121310.1590/1980-5373-mr-2017-0783Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous SilicaLeandro Fernandeshttps://orcid.org/0000-0003-0384-3604Rafael Salomãohttps://orcid.org/0000-0003-3392-6857The 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°C) and greater densification during sintering. This paper reports the "in situ" formation of mullite-alumina structures from fine calcined alumina (α-Al2O3) and four grades of SAS of different particles' morphology, specific surface area and internal porosity. After sintering assisted by dilatometry (up to 1500°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°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.http://www.scielo.br/pdf/mr/v21n3/1516-1439-mr-1980-5373-MR-2017-0783.pdfSynthetic amorphous silicamullitemicrostructurephysical propertiescalcined aluminadensification |
| spellingShingle | Leandro Fernandes Rafael Salomão Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica Materials Research Synthetic amorphous silica mullite microstructure physical properties calcined alumina densification |
| title | Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica |
| title_full | Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica |
| title_fullStr | Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica |
| title_full_unstemmed | Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica |
| title_short | Preparation and Characterization of Mullite-Alumina Structures Formed "In Situ" from Calcined Alumina and Different Grades of Synthetic Amorphous Silica |
| title_sort | preparation and characterization of mullite alumina structures formed in situ from calcined alumina and different grades of synthetic amorphous silica |
| topic | Synthetic amorphous silica mullite microstructure physical properties calcined alumina densification |
| url | http://www.scielo.br/pdf/mr/v21n3/1516-1439-mr-1980-5373-MR-2017-0783.pdf |
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