Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
J. Phys. IV France 03 (1993) C7-1311-C7-1316
Preparation of alumina-chromium composites by reactive hot-pressing A1 + Cr2O3 based powdersD. OSSO, A. MOCELLIN, G. LE CAER and A. PIANELLI
LSG2M, URA 159 du CNRS, Ecole des Mines, 54042 Nancy cedex, France
Chromium-Alumina based composites have been obtained by reactive sintering under load and vacuum of various powder blends. The starting mixtures have been prepared from commercially available aluminium metal, chromium and aluminium oxides, and a thermally unstable titanium compound respectively. Differential thermal analysis (DTA) and differential calorimetry (DSC) as well as X-ray diffraction were used to identify chemical transformations taking place within the system. Microstructure changes were observed via scanning electron microscopy (SEM) with an energy dispersive spectroscopy system (EDS). Chemical reactions in relevant binary subsystems have been investigated qualitatively in order to understand the course of events in the more complex quaternary mixtures. The possibilities of forming intermetallic phases in both the Al-Ti and Cr-Ti systems and of dissolving some Cr2O3 into the product Al2O3 phase have been considered. The influence of such parameters as thermal schedule and initial aluminium content on those side reactions and the resulting microstructures was investigated.
© EDP Sciences 1993