Time-Dependent Nucleation in Undercooled Pd_(43)Cu_(27)Ni_(10)P_(20) Melt

摘要

This work presents time-dependent nucleation which describes the experimental results of the crystallization in bulk glass-forming Pd_(43)Cu_(27)Ni_(10)P_(20) melts reported by Schroers et al. [J. Schroers, Y. Wu, R. Busch, and W.L. Johnson, Acta Mater. 49, 2773 (2001)]. It reveals that due to high growth rate at high temperature, crystallization of sample could occur before the equilibrium cluster distribution is established. The implications of the result will be that (1) nucleation-involved phase transformations (e.g., liquid-to-solid, amorphous-to-crystalline, and crystalline-to-crystalline transformations) in systems, including metallic, ceramic, polymer, bio-systems, could be governed by time-dependent nucleation in undercooled liquids. (2) The parameter of steady-state nucleation rate defined in the classic nucleation theory has no physical meaning at high temperatures (or at temperatures with small undecooling from liquid). The real nucleation rate at a given time and temperature should be considered.