FORMATION OF GLASSY SPHERES OF FE-NI-P-B BY CONTAINERLESS PROCESSING

The undercooling behaviour and the glass-forming ability of Fe40Ni40P14B6 melts have been investigated after heterogeneous nucleation was reduced by a fair amount through the application of the melt fluxing method or a drop tube. The undercooling shows a strong dependence on the overheating temperature leading to a maximum undercooling of 320 K. Analogously, the glass-forming ability to drop tube processes droplets increases significantly, when the melt is overheated by 250 K above the melting temperature. Under such conditions the preparation of glassy spheres in diameter up to 300-mu-m is possible.