Sol-Gel-Processing of nanostructered ceramic and ceramic/metal composite materials

D. Sporn, J. Grossmann, Andreas Kaiser, R. Jahn, A. Berger

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Sol-gel methods were used for the preparation of powders, films and bulk materials consisting of nanosized crystallites. Powders in the systems BaTiO3 and TiO2 were produced by applying a lyothermal treatment of gels. This led to powders with crystallite sizes between 15 and 700 nm, depending on the chosen reaction conditions. By using zirconia containing sols as precursor of ZrO2 films on steel, it could be observed that, after thermal treatment up to 600 °C, the film microstructure consisted of densly packed tetragonal ZrO2 crystallites of 10 nm in diameter. The application of nanostructured mullite (3 Al2O3·2 SiO2) films on the surface of carbon fibres improved their thermal stability in normal atmosphere. It was found that mullite coated C-fibres are able to survive thermal treatments up to 840 °C in normal atmosphere. The use of sol-gel methods in ceramic/metal composite materials (e.g. Ni/c-ZrO2) generated powders consisting of Ni crystallites of 10 – 30 nm, which were embedded in a matrix of c-ZrO2 crystallites with 5 – 10 nm in diameter. The densified samples exhibited a bending strength up to 490 MPa and a fracture toughness up to 9 MPa·m112

Original languageEnglish
JournalNanostructured Materials
Volume6
Pages (from-to)329-332
ISSN0965-0773
DOIs
Publication statusPublished - 1995
Externally publishedYes

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