Abstract

Al-Cu-Fe alloys were prepared by mechanical alloying starting from elemental powders in a high-energy planetary ball mill. Three different alloy compositions with the same c Cu : c Fe ratio of 2 : 1 but different aluminium contents, that is Al 55 Cu 30 Fe 15 , Al 63 Cu 25 Fe 12 and Al 70 Cu 20 Fe 10 , were investigated. A sequence of solid-state reactions resulting in quasicrystalline phase formation in Al 63 Cu 25 Fe 12 proceeds during milling and during annealing of the as-milled powder. These reactions were studied by X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. In order to form an aluminium-matrix composite, Al 63 Cu 25 Fe 12 single-phase quasicrystalline powders were blended with different amounts of aluminium. In an intermediate milling step the powder blend was homogenized. The powders were consolidated by hot extrusion. The bulk samples revealed a homogeneous dispersion of the particles in the matrix but a rather heterogeneous size distribution. The mechanical properties at room temperature were tested by constant-rate compression tests. A rule-of-mixtures dependence of the ultimate strength and the yield strength on the volume fraction of the quasicrystalline particles was found