In PanEvolution, KWN model is based on the Kampmann and Wagner’s work as implemented in a numerical framework, and extended to handle both homogeneous and heterogeneous nucleation, dealing with various morphologies for the simulation of precipitation kinetics of multi-component alloys under arbitrary heat treatment conditions. The following is a brief introduction to the KWN model along with its sub-models for nucleation, growth and coarsening.
Specifically, in the KWN model the continuous PSD is divided into a large number of size classes. The program takes a simulation step at every sample time hit. To maintain both accuracy and efficiency between two adjacent simulation steps, a fifth-order Runge-Kutta scheme is used to generate an adaptive step size based on the continuity equation.
Please note that all the variables used in the equations in this section are summarized in the tables in Section PanEvolution tables. Please refer to these tables and examples in Section The Kinetic Parameters Database (KDB file) Syntax and Examples for setting up these variables in the KDB files.
Precipitation Strengthening Model
Precipitation Hardening Model with Multiple Particle Groups
Evolution of Dislocation Density
The JMAK Model for Recrystallization
The Fast-Acting Physical Model for Recrystallization