Metastable phase accompanying crystallisation of amorphous Al 85 Ni 10 Ce 5 alloy

Abstract

Isochronal annealing and isothermal annealing of melt spun amorphous Al₈₅Ni₁₀Ce₅ alloy were carried out to investigate the crystallisation behaviour. It has been found that a metastable phase occurring in the crystallisation process, may exist for a certain time but in due course disappears either acting as a nucleus of another phase or transforming into another stable phase with an increase in either annealing temperature or annealing time. Transmission electron microscopy results reveal that Al₃Ce may be one of the metastable phases during the isochronal annealing process. Furthermore, microhardness measurements reveal that the specimens containing metastable phases exhibit higher microhardness than the as quenched and as crystallised alloy.