Nucleation in undercooled Zr41Ti14Cu12Ni10Be23 melts

The undercooling and solidification of bulk glass forming Zr41Ti14Cu12Ni10B e23 liquids is investigated by processing in high purity graphite crucibles . Isothermal nucleation studies are performed between the liquidus and the glass transition temperature. The resulting time-temperature-transformation diagram is similar to the diagram obtained from containerlessly processed samples. Heterogeneous surface nucleation at the container walls does not e ffect the crystallization. The solidification products of these differently processed specimens are investigated by scanning electron microscopy as we ll as by electron microprobe. The investigations reveal the morphology and typical length scale of the microstructure after crystallization at differe nt degrees of undercooling. The number density of nuclei during primary cry stallization is estimated from the microstructure. (C) 1999 Published by El sevier Science B.V. All rights reserved.