FORMATION OF BULK METALLIC GLASS Pd 40.5 Ni 40.5 P 19 BY SOLIDIFICATION WITHOUT CONTAINER IN A DROPPING TUBE

The dispersed molten droplets of Pd 40.5 Ni 40.5 P 19 alloy solidified during fall down in a 1.2 m drop-tube which is filled with purified helium at 0.8 atmosphere. Owing to solidificat ion without container occurring at high undercooling, the heterogeneous nucleation was inhibited and the metallic glass sphere of 2 mm in diameter was obtained, which is the largest one prepared by dropping tube up to now.