A HIGH SPEED CINEMATOGRAPHY STUDY OF RAPID SOLIDIFICATION
快速凝固过程的高速摄影研究

Ni-32.5%Sn eutectic alloy has been undercooled by up to 302K(0.215T_E)throughdenucleating with a special boron-silicate glass 70% Na_2SiO_3+17.7% Na_2B_4O_7+12.3%B_2O_3.Its rapidsolidification behaviour during recalescence was studied by means of high speed cinematography andrapid infrared pyrometry,It is found that interface heterogeneous nucleation takes place in preferenceto homogeneous nucleation even at an undercooling above the previously accepted critical undercool-ing 0.2T_mfor homogeneous nucleation,and that the transient solidification velocity attains 784mm/s.