Nucleation modes of the drop tube processed Nd70Fe20Al10 droplets

Abstract

The Nd70Fe20Al10 bulk metallic glass forming alloy was processed by the drop tube processing (DTP) method. Droplets consisted of mixed crystalline and amorphous phases, and an anomaly in the plot of droplet size vs. heat of crystallization was observed by thermal analysis. To understand this, a surface heterogeneous nucleation model which follows from the surface oxidation during DTP was suggested. And three representative nucleation mechanisms in DTP such as homogeneous, volume heterogeneous, and surface heterogeneous mechanism were discussed qualitatively. (C) 2003 Elsevier B.V. All rights reserved.