# Grain Growth¶

The examples T020_Grain_Growth_initialFromFile, T022_Grain_Growth_Pinning_Pres and T023_Grain_Growth_Solute_Drag show how MICRESS® can be used without coupling to external fields like temperature or concentration, i.e. using only the curvature as a driving force for the transformation. Respective curvature based coarsening is inherent to phase-field models. These examples also show how to read-in initial microstructures.

The T020_Grain_Growth_initialFromFile example displays pure grain growth, whereas the other examples draw on specific models hindering grain boundary motion like e.g. the particle pinning, the solute-drag and KTH-solute-drag models, respectively.

In addition, grain growth with non-linear temperature profiles is modeled in the T021_Grain_Growth_Profiles example.

The example T024_Grain_Growth_Solute_Drag_dG is the same as T023_Grain_Growth_Solute_Drag apart from the mobility which is not constant but dependent on the driving force.

## Alloy¶

The alloy system and composition are not specified.

## Simulation conditions¶

ExampleT020T021T022T023T024
Dimension 2-D
Grid size 400x320 cells100x500 cells400x320 cells
Grid spacing 1.5 microns
Interface thickness 5 cells
Boundary conditions Phase field
• east = periodic
• west = periodic
• top = periodic
• bottom = periodic
Solid phases one phase

## Results¶

### Pure grain growth¶

T025_GrainGrowth grain growth sequence

$t = 0s$ $t = 500s$ $t = 1000s$

### Grain growth with particle pinning¶

T022_Grain_Growth_Pinning_Pres grain growth sequence

$t = 0s$ $t = 500s$ $t = 1000s$

### Grain growth with solute drag¶

T023_Grain_Growth_Solute_Drag grain growth sequence

$t = 0s$ $t = 500s$ $t = 1000s$

### Grain growth with solute drag and driving force dependent mobility¶

T024_Grain_Growth_Solute_Drag_dG grain growth sequence

$t = 0s$ $t = 500s$ $t = 1000s$

### Grain growth with temperature dependent mobility¶

T021_Grain_Growth_Profiles grain growth sequence

$t = 0s$ $t = 0.32s$ $t = 1s$

T021_Grain_Growth_Profiles temperature profile sequence

$t = 0s$ $t = 0.32s$ $t = 1s$

### Grain growth with low-angle misorientation in 3D¶

This example demonstrates how to treat low-angle misorientation based on the models of Humphreys and Read-Shockley, as well as how to distinguish high-angle boundaries with special misorientation such as ${\sum}\,3$ and ${\sum}\,9$ boundaries using the misorientation model.

T029_Grain_Growth_Misorientation_3D grain growth sequence showing low-angle boundaries (blue), ${\sum}\,3$ boundaries (red) and ${\sum}\,9$ boundaries (green)

$t = 0s$ $t = 250s$ $t = 500s$ $t = 1000s$