Ceramics-Silikáty 53, (3) 205 - 210 (2009) |
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ELABORATION AND CHARACTERIZATION OF MULLITE-ZIRCONIA COMPOSITES FROM GIBBSITE, BOEHMITE AND ZIRCON |
Belhouchet Hocine 1, Hamidouche Mohamed 2, Bouaouadja Noureddine 2,
Garnier Vincent 3,
Fantozzi Gilbert 3 |
1 Department of Physics, Mohamed Boudiaf University, 28000, M’sila, Algeria
2 Laboratoire des Matériaux Non Métalliques, Département d‘Optique et de Mécanique de Précision,
Faculté des Sciences de l‘Ingénieur, Université Ferhat Abbas 19000 Sétif, Algérie
3 Laboratoire MATEIS, INSA de Lyon, 69621 Villeurbanne, France
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Keywords: Gibbsite, Boehmite, Mullite-zirconia, Reaction-sintering, Composites, Microcracks |
In this study we prepared mullite-zirconia composites by reactive sintering of gibbsite and boehmite as alumina sources and
zircon powder. All raw materials have been ball milled and isostatically pressed followed by sintering in the temperature
range of 1400-1600°C during 2 h of soaking. Then the sintered samples have been characterized by X-ray diffraction,
ATD/TG analysis and microstructural observation. X-ray diffraction peaks showed the formation of mullite-zirconia composites
in both mixtures. The microstructure of all composites was composed of irregularly shaped mullite grains and roundshaped
zirconia grains, which are distributed intragranularly and intergranularly. These microstructures had microcracks
in the samples prepared from gibbsite and zircon, contrary to the samples prepared from boehmite and zircon where no
microcracks were present. These microcracks are caused by evaporation of structure water at 300°C. So the preparation of
mullite-zirconia composites with the substitution of the α-alumina by the boehmite is feasible. |
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