The transformation dialog can be used to create 'solid transformations'. These represent recipes for how one phase in a *MatCalc* simulation ought to be transformed into another one. Typical application of transformations are the transformation of delta-ferrite into austenite in the Scheil simulation of peritectic reactions in steel (see, e.g., example *E20-3* - Accounting for the peritectic reaction), or the transformation of one matrix phase into another one when evaluating the heat capacity of systems during DSC experiments.

A transformation is typically applied to phases which have *dormant* phase status. The transformation can occur according to different strategies

- The standard
**full equilibrium**or**constrained (para-) equilibrium**condition is used to determine the phase fractions as a result of an equilibrium simulation. This is the common selection when using transformations in Scheil-Gulliver simulations. - Alternatively, the transformation can be performed according to an
**Avrami equation**with parameters $n$ and $k$. The transformed fraction $f$ is evaluated from the equation

\[ f = 1-exp(-kx^n) \]

The limits of the transformation are defined by the transformation start and end temperature. - For martensitic transformations, the Koistinen-Marburger equation can be used also. The transformation is then evaluated from

\[ f=1-exp(-n(M_s-T))\]

The limits of the transformation are given by the transformation start temperature, which is interpreted as the martensite start temperature $M_s$. The end temperature is not used in the Koistinen-Marburger equation. - For highest flexibility, the transformation progress can also be defined in terms of a table, where the phase fraction of the product phase is given in terms of X/Y pairs between the limits of the transformation start and end temperature.

Below, the dialog options are described in more detail.

**Create new transformation**: Create a new transformation object.**Remove**: remove existing transformation.**Rename**: rename existing transformation.**Transform From**: A transformation always involves one phase which will be transformed into another. This selection defines the parent phase.**Transform To**: Product phase, into which the parent phase will be transformed.**Transformation equilibrium phase**: When using the transformation options*full equilibrium*and*constrained equilibrium*, an equilibrium phase must be created that is used to evaluate the transformed fraction. This phase can be created automatically by using the*Create transformation equilibrium phase*button.**Create transformation equilibrium phase**: Creates a transformation phase with the suffix '_T' and a transformation solid phase with the suffix '_TS'.**Maximum phase fraction**: Usually, the transformation converts the entire parent phase into a product phase. With this setting, the total transformed fraction can be limited to a smaller value.**Status**: When selecting 'active', the transformation will be applied in the next simulation.**Full equilibrium**: The full, unconstrained equilibrium simulation will be used to evaluate the transformed fraction.**Constrained equilibrium**: Para-equilibrium will be used to evaluate the transformed fraction.**Avrami type**: Selection of this option activates the Avrami equation for controlling the transformation progress.**n-factor for Avrami type**: $n$ value in Avrami equation.**k-factor for Avrami type**: $k$ value in Avrami equation.**Koistinen-Marburger type**: Selection of this option activates the Koistinen-Marburger equation for controlling the transformation progress.**n-factor for Koistinen-Marburger type**: $n$ value in Avrami equation.**Manual ratio**: Use a table to control the transformation progress.**data from table**: Corresponding table name.**Start temperature**: Apply transformation only below the start temperature.**Stop temperature**: Finish transformation at the stop temperature.**Temperature in Celsius**: C ↔ K.