Influence of a supercooled liquid on crystallization behaviour of Al-Y-Ni-Co metallic glass

摘要

The present paper aims to report an effect of a supercooled liquid region on crystallization behaviour of an Al_(85)Y_8Ni_5Co_2 metallic glass produced by rapid solidification of the melt. It is found that crystallization behaviour of the above-mentioned Al-based metallic glass, above glass-transition temperature and below it, follows different transformation mechanisms. Formation of the primary nanoscale alpha-Al particles observed during continuous heating, or after annealing above glass-transition temperature, does not occur by the crystallization reaction during isothermal annealing below glass-transition temperature. At such conditions, an unknown metastable phase is formed conjointly with alpha-Al by the eutectic-like mechanism.