Influence of Thermal Treatment of Ni-P Melt on Structure of Amorphous Alloys

Abstract

The structure of amorphous metallic glasses prepared by rapid melt quenching on the rotating drum is sensitive to processing parameters. Many physical properties of amorphous metallic alloys (magnetic, electric and mechanical) are also dependent on the structure. Morphology of fracture surfaces for ribbons of amorphous alloy Ni₈₁P₁₉ prepared from differently thermally treated melts was observed. The highest fracture stress was observed for the ribbon prepared from the melt subjected to the combined thermal treatment. The side of the ribbon which is in contact with rotating wheel during the quenching shows to be partially brittle. Initiations of a chevron type fracture are localized near this surface. The opposite side of the ribbon always failed through meniscus instability mechanism. This difference is considered to be caused by the changes in the melt atomic structure under heating above the critical temperature and after quenching it is preserved in amorphous alloys.