1 Laboratoire de Science des Matériaux Vitreux, Université de Montpellier II, France
2 Aérospatiale, Saint Médard en Jalles, France
Abstract:
Ceramic materials with a very low thermal expansion coefficient are synthesized by the sol-gel process. The binary gel is obtained by hydrolysis and polycondensation reactions of organometallic compounds of aluminium and titanium. The thermal evolution of the amorphous powder is followed by DTA and TGA measurements. Structural evolution is followed using X-ray diffraction. The crystallization of the TiO2 rutile and Al2O3 corindon starts at 700 and 900°C respectively. The transformation of Al2O3 and TiO2 into Al2TiO5 appears between 1200 and 1300°C. The densification of the powder is performed by the hot pressing process. The shrinkage of the powder was previously followed by dilatometric measurements. The physical properties of the final material are studied as a function of pressing parameters.