Characterization investigations of a melt-spun ternary Al–8Si–5.1Cu (in wt.%) alloy

Abstract

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 nm 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.