selecting a population of grains based on average KAM

[cflynn-code]

Hi all, I have gone through the provided mtex documentation on KAM and am able to implement the provided scripts to plot KAM for an EBSD dataset. I am wondering how I would go about determining the average KAM within single grains and then select a population of grains below a given average KAM? I am ultimately trying to get at using KAM to differentiate relict vs recrystallized grain populations. I appreciate any help.
thanks,
Corey

[kilir]

Hi Corey,

for averaging (or many other functions but not just the mean), see grainMean https://mtex-toolbox.github.io/EBSD.grainMean.html .

Wrt the goal to differentiate rxx/non-rxx grains by some measure of intragranular defect density (gkam, gos, mean GND...); key assumption would be that the rxx reduces such a quantity. I would say this is sound to assume for mechanisms involving grain boundaries moving through the material, e.g. blg and gbm.

Cheers,

Rüdiger

[cflynn-code]

Thank you for the feedback!
I took a look at grainMean and came up with a simple script after the import (below). I think I calculated the avg KAM per grain based on the function description (I am not yet confident in the syntax of inputs and functions). Another issue I am noticing is that if try to select for just 'Quartz-new' the calculated grains bleed into the area off of the map (see images below) which is not the case if I use all of the collected ebsd data. The next step is to select for grain averaged KAM based on a designated threshold value which I believe I can do with a Condition.
%ebsd=ebsd('Quartz-new');

% reconstruct grains
[grains, ebsd.grainId] = calcGrains(ebsd,'angle',10*degree);

% smooth them
grains = smooth(grains,5);

%calculate mean KAM for each grain
kam=grainMean(ebsd, ebsd.KAM/degree,grains);

plot(grains,kam);

colorbar

[kilir]

If you want to restrict your grain reconstruction just to quartz, you can do so without "funny grain growth" by using ebsd=ebsd.gridify before reconstruction - assuming a recent Mtex version.

[cflynn-code]

wow thank you! I was mostly just trying to figure out how to plot average KAM for quartz grains and between your feedback and the 'select grains' documentation I figured it out
much appreciated!

[503048019-lab]

Dear Kilir
Fig.1tif.tif
,

Sorry to bother you. I’m a beginner with MTEX and ORTools, currently using the latest developer version of ORTools, MTEX v5.11.2, and MATLAB R2024b. Using ORTools — Example 7, I’ve generated the Bain map and the CP (child–parent) map for a single reconstructed prior austenite grain. However, I’m not sure how to produce the corresponding KAM map. Could you please help me with this?

Thank you!

[kilir]

Hi,
here's the documentation: https://mtex-toolbox.github.io/EBSDKAM.html
Cheers,
Rüdiger