An Amorphous La₅₅Al₂₅Ni₂₀ Alloy Prepared by Water Quenching

Abstract

A La₅₅Al₂₅Ni₂₀ alloy was found to be amorphized by quenching the melt in a quartz capillary into water and the resulting amorphous alloy in a cylindrical form was obtained in the diameter range below about 1.2 mm. In comparison with thermal properties of a melt-spun amorphous La₅₅Al₂₅Ni₂₀ ribbon, the cylindrical amorphous alloy had a higher onset temperature and a smaller heat evolution of irreversible structural relaxation but no distinct difference in glass transition and crystallization behavior was seen. Thus, the amorphous phase prepared by water quenching had a more relaxed atomic configuration as compared with that for the melt-spun ribbon, but there was no distinct difference in the specific heat curves for both samples reheated up to the supercooled liquid region. This is the first finding that amorphization occurs by water quenching in an alloy without noble metals. The high glass-forming ability is probably due to a high reduced glass transition temperature (T_g⁄T_m) reaching 0.68.