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A Study of the Nucleation Kinetics, Linear Growth and the Overall Crystallization Kinetics of Meltspun Pd 80 Si 20 Amorphous alloy
Author(s) -
Spassov Tony
Publication year - 1992
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170270203
Subject(s) - nucleation , crystallization , kinetics , isothermal process , thermodynamics , amorphous solid , crystallite , materials science , homogeneous , amorphous metal , alloy , isothermal transformation diagram , crystallography , chemistry , microstructure , metallurgy , physics , bainite , austenite , quantum mechanics
Nucleation kinetics, linear growth rate and overall isothermal crystallization kinetics of PdSi amorphous alloy are studied by means of DSC and optical microscopy. It is found that both the histograms of the crystallite sizes and the DSC isotherms (resp. the time dependences of the degree of transformation α( t )) are best described by the model comprosing the simultaneous occurrence of two reactions of crystallization: heterogeneous as well as homogeneous non‐stationary nucleation with subsequent three‐dimensional growth in both cases. From the fit of the experimentally measured and the calculated according the model thus proposed distribution curves N i (Φ) the stationary rates of heterogeneous and homogeneous nucleation, the number of quenched‐in nucleation sites and the transient time lags of heterogeneous and homogeneous nucleation have been estimated. Using the values of these parameters kintic curves degree of transformation vs. time have been generated, which are closed to the exerimental x ( t ) curves obtained by means of DSC at isothermal conditions.