Microstructural characterization of a rapidly solidified Al–Sr–Ti alloy

The microstructure of the melt-spun Al–7Sr–3Ti alloy has been characterized using X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. The results show the microstructure of the melt-spun Al–7Sr–3Ti alloy is composed of the equilibrium α-Al, Al4Sr, Al3Ti and metastable Al23Ti9, different from that of the ingot-like alloy comprising α-Al, Al4Sr and Al3Ti. Moreover, the amount of Al3Ti is much less than that of Al4Sr and metastable Al23Ti9 in the melt-spun alloy. The melting temperature of primary phases and enthalpies of fusion for the melt-spun Al–7Sr–3Ti alloy are lower than those for the ingot-like alloy. The formation mechanism of the microstructure of the melt-spun alloy has also been discussed.