Characterisation of some kaolins in relationship with electric insulator ceramics microstructure
Various types of kaolins as representative raw materials for electric insulator ceramics were investigated in order to establish their influence on ceramics' properties, defects and microstructure. The raw samples were chemically-investigated (AAS), and tested by X-ray diffraction (XRD) and the...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
Department of Mineralogy, Geochemistry and Petrology, University of Szeged
Szeged
2005
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| Sorozat: | Acta mineralogica-petrographica
46 |
| Kulcsszavak: | Földtan, Ásványtan, Kőzettan |
| Tárgyszavak: | |
| Online Access: | http://acta.bibl.u-szeged.hu/25136 |
| Tartalmi kivonat: | Various types of kaolins as representative raw materials for electric insulator ceramics were investigated in order to establish their influence on ceramics' properties, defects and microstructure. The raw samples were chemically-investigated (AAS), and tested by X-ray diffraction (XRD) and thermal analysis (DTA and TG) in order to define their mineralogical composition and structural characteristics. The thermal treatment of the kaolins and of the ceramic mixture was carried out at 1300 °C. The microstructure resulted after firing was studied by optical and electron microscopy. The chemical composition of the amorphous phases of the ceramic body was studied by EDS; by processing the data acquired, some inhomogeneity in the microstructure of the ceramic body was established. It is concluded that the final microstructure, defects and properties of the ceramic products are influenced by the chemical and mineralogical composition of the raw materials. The impurities present (namely Fe-bearing phases) have a great influence on the electric properties of the ceramics. The mineral phases present in kaolins play a significant role in selecting the wet methods used for preparing the ceramic masses (presence of interstratified I/S increases the plasticity, but also the fired shrinkage), and the crystalline phase formation during thermal treatment (formation of poor- or well-crystallized mullite and cristobalite). |
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| Terjedelem/Fizikai jellemzők: | 9-14 |
| ISSN: | 0365-8066 |