Thermal expansion of beta-eucryptite in oxide-based ceramic composites

A. Pelletant (1) , H. Reveron (1) , Jérome Chevalier (2, 1) , Gilbert Fantozzi (1) , F. Guinot (3) , L. Blanchard , F. Falzon (3)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 CSTB - Centre Scientifique et Technique du Bâtiment
3 TAS - Thales Alenia Space [Toulouse]

This paper presents an experimental investigation on the thermal expansion behaviour of beta-eucryptite (E) when it is used for processing alumina/beta-eucryptite (AE) or zirconia/beta-eucryptite (ZE) composites. Composite materials were prepared from a beta-eucryptite powder synthetised in our laboratory and commercially available alumina or zirconia nanopowders. In order to preserve the beta-eucryptite crystalline phase in sintered materials, the pressureless sintered step was performed at relatively low temperatures (<1300 degrees C). It is experimentally shown that in well-densified oxide-based composites, the beta-eucryptite lost its slightly negative thermal expansion coefficient. This behaviour could be related to compressive residual stresses applied on beta-eucryptite grains due to the thermal expansion mismatch between alumina or zirconia and the beta-eucryptite. (C) 2012 Elsevier Ltd. All rights reserved.

Mots clés: Composites; Thermal expansion; Mechanical properties; Al2O3; beta-Eucryptite

Domaines: Matériaux

A. Pelletant, H. Reveron, Jérome Chevalier, Gilbert Fantozzi, F. Guinot, et al.. Thermal expansion of beta-eucryptite in oxide-based ceramic composites. Journal of the European Ceramic Society, 2013, 33 (3), pp.531-538. ⟨10.1016/j.jeurceramsoc.2012.09.022⟩. ⟨hal-01814433⟩