The Kinetic Parameters Database (KDB file) Syntax and Examples

The kinetic parameters database (.KDB file) uses the XML format, which defines the kinetic model for each precipitate phase and its corresponding model parameters such as interfacial energy, molar volume, nucleation type, morphology type, and so on. In the KDB, a series of alloys can be defined. Each alloy has a matrix phase with one or multiple precipitate phases. A sample kdb structure is shown as follows,

<Alloy name="Fe-Mn-C">

<MatrixPhase name="Bcc">

  <ParameterTable type="kinetic" name="Parameters for Bcc">

</ParameterTable >

  <PrecipitatePhase name="Cementite_GB"

phase_name="Cementite" model="kwn"

   morphology="Sphere" nucleation="Grain_Boundary" growth="simp">

   <ParameterTable type="kinetic" name="Parameters for Cementite">

    <Parameter type="Molar_Volume" value="6E-6" description="Molar Volume" />

    <Parameter type="Interfacial_Energy" value="0.2"

description="Interfacial Energy" />

    </ParameterTable >

  </PrecipitatePhase >

  <PrecipitatePhase name="M7C3_GB" phase_name="M7C3" model="kwn"

   morphology="Sphere" nucleation="Grain_Boundary"  growth="simp">

   <ParameterTable type="kinetic" name="Parameters for M7C3">

    <Parameter type="Molar_Volume" value="6E-6"

description="Molar Volume" />

    <Parameter type="Interfacial_Energy" value="0.1" description=

      "Interfacial Energy" />

    </ParameterTable >

   </PrecipitatePhase >

   </MatrixPhase >

</Alloy >

In this sample KDB, an alloy “Fe-Mn-C” is defined with the matrix phase “Bcc”, which has two precipitate phases “Cementite_GB” and “M7C3_GB”. The precipitate name, kinetic model, morphology, as well as nucleation and growth model can be defined for each precipitate phase. Available options for the kinetic models and morphology are given in Table 2 in Section PanEvolution tables. A set of parameters for each phase, such as molar volume, interfacial energy, and so on, can be defined in “ParameterTable”. The kinetic and mechanical model parameters that can be defined under “ParameterTable” are listed in Table 4 to Table 7 in Section PanEvolution tables.

A few examples are given below to explain the content of the precipitation database in detail. In the reference folder, test batch files (.pbfx) are prepared with .kdb files for running example simulations.