Undercooling and solidification of Ni₇₇P₂₃ alloy in a 52-m drop tube

This paper applies techniques of containerless processing, drop tube and glass fluxing, to undercool and solidify Ni₇₇P₂₃ alloys. Different diameter spheres were collected at the bottom of a 52-m long drop tube. Both crystalline and amorphous phase were formed in various size specimens due to the different cooling rate. The variation of partial undercooling with bulk undercooling is calculated for the Ni₇₇P₂₃ alloys. The deep undercooling and rapid solidification behaviour of Ni₇₇P₂₃ melts has been analysed with respect to microstructure formation and transition during fluxing and 52-m drop process of undercooled melts.