About Phases

This section or topic is specific to Console Mode.

For Graphical Mode, see Diffusion Module Terminology in Graphical Mode.

Entering Phases in Regions and Specifying Phase Compositions in a Region.

Each region contains one or more phases. A phase can be of the matrix, spheroid or lamellar type. A phase can be introduced with the status active (the default) or inactive.

An inactive phase is a phase which does not participate in the calculations until it is stable. If a phase is inactive, then the driving force for precipitation of the phase is continuously monitored. When the driving force exceeds a predefined positive value, the phase take parts in the simulation and the phase automatically becomes active. A new region is then created and the formerly inactive phase is entered as the matrix phase of the new region. The name of the region is set to the name of the phase that just became active but with R_ added as a prefix.

Region Phase Types

Phase type	Description
Matrix	The region’s primary phase. If there is only one phase in a region, then that phase is automatically a matrix.
Spheroid	Used to treat one or several dispersed phases in a matrix. Unless the homogenization model is invoked, which happens automatically when a spheroid phase is entered, then diffusion is only considered in the matrix phase; the spheroid phases then only act as sources and sinks of the diffusing elements.
Lamellar	Used to simulate the growth of a eutectic or eutectoid region. The software only treats the growth, not the dissolution, of such a region. The pearlite calculation model is used for a phase that is lamellar.