October 12th 3D HEDM Data

High Energy X-Ray Diffraction Microscopy (I believe I've mentioned it previously before) is an amazing technique which allows non-destructive 3D characterization of a microstructure. Chris Hefferan recently defended his thesis on studying the annealing of pure nickel. This is very similar to my project, although at the same time a more general understanding of whether this technique can be used to observe grain growth changes as well as any change in the grain boundary character. Of course, the most readily apparent observation is the saturation of Sigma3 boundaries in the microstructure. This was further investigated to determine if it was just the increase volume of Sigma3 boundaries in the microstructure, or if more boundaries were becoming closer in alignment to the Sigma3 nature. It turned out that the first had very little contribution, while the second played a much more major role.

I recently obtained a copy of the data of the sample in its fourth annealing state. The goal is to compare the twin morphologies found in this 3D data set to both what Yuan and I were trying to achieve, and any other data set we can find out there, and determine a scheme for classifying twins in 3D.

The .vtk file of the data is 2.5 GBs.

...

ParaView has crashed two or three times dealing with the size of this data, but the few times I have managed to get it to fully work, this thing is an absolute monstrosity. The number of grains in the sample are impressive as well as their well-defined shape prior to any smoothing/meshing. There are well over 10,000 grains in the system, which each time I attempt to threshold the sample, I watch in fear of the rainbow cursor spinning indefinitely. However, here are some preliminary attempts, in which we can clearly see we conserve the corner twin on the left and the complete twin regardless of how we approach the slice:

What's immediately interesting already is the lack of well defined, straight coherent twin boundaries. Instead, depending on both how and where we slice it, we can have different degrees of steps/facets in the 2D image. Back to more investigation!