EBSD Output format

[KamalnathOSU]

Dear MOOSE team,

In the Phase-field examples, we can take input from EBSD data and perform grain growth simulation (eg: IN100-111grn.i. Is there a way in which we can get the final microstructure in EBSD format?

Thanks,
Kamal

[laagesen]

We don't have the capability to do this currently- can you explain a bit more about what you are wanting to do? We may be able to suggest another route to accomplish it.

[KamalnathOSU]

I am trying to study the growth of an amorphous (A) phase in a polycrystalline material ( G_1, G_2, G_3, ..., G_M ) at room temperature where grain growth can be neglected. The amorphous phase has significant growth rate even at room temperature. Hence, I want to freeze the grain structure during the evolution of the amorphous phase A. The amorphous phase interface with the solid grain (referred to as A-G_i ; i=1,2,..,M) has anisotropic mobility and it depends only on the orientation of the grain.

I planned my simulation in two steps.

Step1 : I generated a polycrystal structure from Dream.3D, relaxed it (to get diffuse interface) with phase-field module and got output of the microstructure. I was able to accomplish this step.

Step2 : Load the relaxed polycrystal microstructure and simulate the growth of the amorphous phase. Here, I need to specify the anisotropic mobility of A-G_i in terms of the grain orientation. For this purpose, I need to know the number of grains co-existing in a nodal point and its corresponding orientation.

Can you please suggest me how to accomplish "Step2" ?

[laagesen]

We don't currently have the capability to do exactly what you are trying; however, you could probably write some new code based on existing code. We do have the capability to set different grain boundary energies for different orientations, so you could use a similar approach to that code. Have a look at the documentation page https://mooseframework.inl.gov/modules/phase_field/Grain_Boundary_Anisotropy.html

[KamalnathOSU]

Hi,
I have another question on this topic. After I complete my grain growth simulation, I want to the load the grain structure into AuxVariable and perform some calculations with it.

1)How to the load the order parameters in AuxVariable ? The usual instructions will allow me to load the order parameters only in NonLinearVariable.

2)How to load the euler angles corresponding to each grain ?

-Kamal

[laagesen]

1. if you want to put an order parameter into an AuxVariable, you can use a ParsedAux AuxKernel. You would need to create an AuxVariable, then use the AuxKernel with args = 'eta0' and function = 'eta1' for order parameter eta1.
2. You can use the OutputEulerAngles AuxKernel to do this. There are other objects that would be needed; have a look at moose/modules/phase_field/test/tests/grain_tracker_test/grain_tracker_ebsd.i for an example.