Heat treatment of rapidly solidified Al-Ni-Mm alloys

Amorphous structure has been obtained in melt-spun Al-Ni-Mm alloys containing less than 5 wt.% Mm content. The tendency to form amorphous structure in the as-melt-spun Al(29− x)wt.%Ni(x)wt.%Mm (x = 3, 4, 5 wt.%) ribbons increases with increasing Mm/Ni ratio and wheel speed. The crystallization behaviour and microstructural development during the annealing of the amorphous Al-25wt.%Ni-4wt.%Mm alloys have been investigated by a combination of differential scanning calorimetry, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The amorphous Al-25wt,%Ni-4wt.%Mm alloy crystallizes through the initial precipitation of f.c.c.-Al phase from the amorphous matrix in the temperature range 440–500 K, followed by subsequent precipitation of Al3Ni and Al11(Ce,La)3 phases in the temperature range 530–600 K.