Synthesis and mechanical properties of cast quasicrystal-reinforced Al-alloys

We report on the preparation and mechanical properties of Al-based-composites with quasicrystalline particles as reinforcement. Al-Mn-Ce/Fe and Al-Mn-Pd bulk samples were synthesized by die casting into a copper mould at moderate cooling rate. Thin ribbons were prepared by melt-spinning as a reference state for the phase formation under most rapid quenching conditions. Microstructural analysis was done using X-ray diffraction, scanning and transmission electron microscopy as well as calorimetric methods. Significant differences in the phase formation, the composite microstructure and the thermal stability of the microstructure were found for different alloy compositions. The deformation behaviour was characterized by constant-rate compression tests at room temperature for a number of alloy variations yielding excellent properties compared to conventionally produced Al-alloys. The mechanical properties vary within a wide range of strength and ductility as a function of the quasicrystal volume fraction and their morphology. Also first tests at elevated temperatures were carried out, revealing a promising high temperature stability of the composite. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.