Instantaneous growth approximation describing the nanocrystallization process of amorphous alloys: A cellular automata model

Crystallization kinetics and soft magnetic properties in metalloid-free (Fe, Co)90Zr10 amorphous and nanocrystalline alloys

“…This indicates that nucleation is enhanced and grain growth is more constrained in the Co containing alloy with respect to the Co-free one, in agreement with the observed reduction in crystal size after partial Co substitution for Fe in B-containing NC alloys [11,12]. This is ascribed to the non-preferential partitioning of Co into the crystalline phase [13,14], which implies a higher relative Fe enrichment of the crystallites in Co containing samples with respect to Cofree ones, limiting their growth due to a fast depletion in Fe of the vicinity of a growing bcc Fe(Co) crystal [15]. [16,17].…”

Correlation between microstructure and temperature dependence of magnetic properties in Fe60Co18(Nb,Zr)6B15Cu1 alloy series

“…This can be understood in the frame of a recently proposed crystallization mechanism for these nanocrystalline systems based on continuous nucleation and instantaneous growth processes. 23,24 This mechanism predicts faster crystallization kinetics ͑al-though slow in comparison with conventional nucleation and three dimensional growth mechanisms͒ at the very beginning of nanocrystallization process, characterized by an Avrami exponent close to 1, which decreases as nanocrystallization progresses. The slowing down of the kinetics after the early stages of nanocrystallization can be correlated with a larger enthalpy per Fe atom incorporated to crystalline sites, i.e., with a more difficult mechanism of crystallization.…”

“…These small changes are in agreement with the instantaneous growth approximation describing the nanocrystallization kinetics of this kind of alloy. 23,24 Under this approach, the time required for a nanocrystal to achieve its final size is negligible in comparison with the time of nanocrystallization process.…”

Analysis of nanocrystallization kinetics and crystal size distribution under limited growth approach

“…observed that crystal size saturation is achieved much earlier than saturation in crystalline fraction and that nucleation occurs till the final stages of the process. These characteristics are typical for nanocrystallization processes and yield the instantaneous growth approximation [6].…”

“…In this work, limited growth approach is analyzed using two different simulation models: crystallization of a space divided in cubic cells (Cell-Sim) [5,6] and crystallization of a continuous space (Cont-Sim) where an average soft impingement is considered. Both assume the formation of a Fe rich crystalline phase.…”