The Metal Phase Transformation Interface
The Metal Phase Transformation interface () is found under the Heat Transfer>Metal Processing () branch when adding a physics interface. The physics interface is intended for studying metallurgical phase transformations. You can use this interface to study diffusional, displacive, and user-defined (solid state) phase transformations. Physical phenomena, such as latent heat of phase transformation and transformation strains, can be computed and used in Heat Transfer in Solids and Solid Mechanics. With the Nonlinear Structural Materials Module or the Geomechanics Module, plastic strains and hardening behavior of each metallurgical phase can be used in Solid Mechanics. Different sections of the Settings panel will be active depending on the space dimension that the interface is used in, see Table 4-1.
When the Metal Phase Transformation interface is added, three nodes are also added to the Model Builder — two Metallurgical Phase nodes and one Phase Transformation node. The phase transformation node will be set to use the two metallurgical phases as source and destination phases, respectively. From the Physics toolbar, you can add additional metallurgical phases and phase transformations. You can also right-click Metal Phase Transformation to select physics features from the context menu.
Settings
The Label is the default physics interface name.
The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.
The default Name (for the first physics interface in the model) is metp.
Material Properties
You have the option of letting the physics interface compute effective thermal, electromagnetic, and mechanical material properties, based on the corresponding properties and fractions of the individual metallurgical phases. Select the Compute effective thermal properties check box to let the physics interface compute effective thermal properties. Select the Compute effective electromagnetic properties check box to let the physics interface compute effective electromagnetic properties. Select the Compute effective mechanical properties check box to let the physics interface compute effective mechanical properties. You can use the computed effective material properties to create a compound material that can be used in other physics interfaces as a domain material. Select the Create Compound Material to create a compound material. This material is created at the component level.
Heat Transfer
Phase transformations are inherently temperature dependent. Select the temperature field to use from the Temperature list. If you want to consider the release or absorption of latent heat during phase transformations, select the Enable phase transformation latent heat check box. You can then define values for the latent heat at each of the phase transformation nodes. By default, the check box is not selected.
Temperature
Phase transformations are inherently temperature dependent. Enter an expression for the temperature to use.
Solid Mechanics
This section contains settings that affect various strains that accompany phase transformations. Select the Enable transformation-induced plasticity check box if you want to include this type of transformation strain in your analysis. The Enable thermal strains and Enable phase plasticity check boxes are visible only if you have selected the Compute effective mechanical properties check box in the Material Properties section. Select Enable thermal strains if you want to include thermal strains in your analysis. Note that the thermal strains will include both pure thermal strains as well as strains that arise from volumetric differences between different metallurgical phases. Select the Enable phase plasticity check box if you want to allow for plasticity in the individual phases. By default, none of the three check boxes in this section are selected.
Advanced
By default, bounds for computed phase fractions and their sum, are checked during a simulation. If you select Advanced Physics Options, the Advanced section is used to modify the bounds that are used, or to disable the bounds checking altogether. When you have selected Check phase fraction bounds, you can modify the:
Maximum phase fraction sum, which defines the numerical upper bound for the phase fraction sum.
Minimum phase fraction sum, which defines the numerical lower bound for the phase fraction sum.
Minimum phase fraction, which defines the numerical lower bound for each phase fraction, individually.
Discretization
The discretization for phase fractions is set using the Discretization for phase fractions list. By default, Linear is selected.
Note that when you set the Discretization for phase fractions to Gauss point data, spatial gradients of the phase fractions will not available. This can be relevant in other physics interfaces, should the gradients of phase fractions be required.