About the Coarsening Property Model
Coarsening is a Property Model available when using the Property Model Calculator in Thermo‑Calc.
In the coarsening regime where the driving force is capillarity, the change of mean particle radius evolves according to the equation:
Following Morral and Purdy [1994Mor], the rate constant of precipitating β phase in a multicomponent α phase is
The mobility matrix M is not the same as the mobilites that can be obtained directly from the Diffusion Module (DICTRA). The M matrix instead corresponds to the L’’ matrix as defined by Andersson and Ågren [1992And].
Using the u-fractions that is defined as
where the summation only is performed over the substitutional elements give the final equation for the coarsening rate coefficient.
The interfacial energy, σ, is calculated using the extended Becker’s model (also available as the Interfacial Energy Property Model).
Configuration Settings
The settings are entered on the Configuration window for the Property Model Calculator and described in Coarsening Property Model Settings.
Example
For an example, see PM_G_02: Coarsening and Interfacial Energy.
References
[1992And] J.-O. Andersson, J. Ågren, Models for numerical treatment of multicomponent diffusion in simple phases. J. Appl. Phys. 72, 1350–1355 (1992).
[1994Mor] J. E. Morral, G. R. Purdy, Particle coarsening in binary and multicomponent alloys. Scr. Metall. Mater. 30, 905–908 (1994).