A ternary Al-8Si-5.1Cu (in wt.%) alloy was rapidly quenched from the melt at cooling rates between 10(6) and 10(7) K/s using the melt-spinning technique. The resulting ribbons were characterized using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and microhardness techniques. On the basis of the Al peak shifts measured in the XRD scans, a solid solubility extension value of 3.83 at.% Si in Al was determined. Whereas SEM investigations showed the presence of dendrites rich in Al, TEM investigations revealed nanosized spherically shaped Si crystals 20-25 mn in size. Both XRD and TEM investigations confirmed the absence of any intermetallic phase formation. The microhardness value of the melt-spun. alloy was measured as 201 kg/mm(2). (C) 2003 Elsevier Science B.V. All rights reserved.