ODF's not matching correct orientations, how to rotate

[Dwayne]

Hi,

I am attempting to reconstruct the ODF's I created using channel5 software hkl from imported EBSD data shown in the attached image. However my ODF's using MATLAB turn out like the second attached image. I am unsure why and my attempts to rotate the ODF haven't worked. 

Here is the code:

psi = calcKernel(grains('Ironbcc').meanOrientation)

odf = calcODF(ebsd('Ironbcc').orientations,'kernel',psi)

CS = crystalSymmetry('cubic')

SS = specimenSymmetry('orthorhombic')

plot(odf,'phi1', [0 45]*degree, 'minmax') %plots the phi1 figure at 0 and 45

mtexColorbar

In importing the EBSD data I have matched the two images in the x-y directions but the orientation colouring is different, perhaps due to different IPF mapping? The third attachment is the plot I have when I use the import wizard and the fourth is the raw ebsd image. 

Thank you for your time.

Dwayne

[Ralf Hielscher]

It would probably useful to have a look at the pole figures in MTEX as well as in your channel5 software. Rotations are most easily spotted in pole figures.

Ralf.

[Dwayne]

Hi,

Sorry for the delayed reply. Hope you had good holidays. I have uploaded the channel5 software image. The next image also attached is the matlab pole figure.

Thank you for your time,
Dwayne

[ruediger Kilian]

Hi,
so how did you define TD and RD in your system (with respect to the map)?
Cheers,
Rüdiger

[Dwayne]

Hi,

Once I am finished in data analysis with EBSD, I export the data into a .crc file which I can then import into Channel5 or MTEX. I have the sample geometry defined in the Acquisition software for EBSD, defining the rolling direction and transverse direction. I have attached the pole figure I get from the acquisition software (AZtec).which had a halfwidth of 10 compared to the 20 I had in Matlab - the [111] direction pole figure seems to match the one MTEX produces. This may mean user error when using Channel5Software. However, I cannot get the correct orientation distribution function in MTEX. The material I am using is electrical steel, using Iron bcc for phase identification. I am sure that the channel5 software produces the correct ODF with goss texture in the Hot Band Anneal stage as shown in my first post and in comparison to literature.

[Ralf Hielscher]

I think the more likely explanation is that AZtec suffers from the same problem as MTEX, i.e., it uses a different reference frame than Channel5. The challenge is to guess the Channel5 reference frame.

1.) To this end it would be nice if you could plot 4 pole figures in Channel5 and the corresponding ones in MTEX.

2.) Another point is that you have plotted phi1 sections in MTEX but phi2 sections in Channel5. These should not coincide :)

3.) You most likely did 2.) because MTEX phi2 sections have a phi1 range 0..360. This is because you have specified no specimen symmetry - which is correct. On the other hand it is very surprising that Channel5 gives a phi1 range from 0..90 degree. This makes only sense for orthorhombic specimen symmetry. However looking at the Channel5 pole figures there is clearly no specimen symmetry. This should be clarified.

Ralf.

[Rüdiger Kilian]

Hi Dwayne,
and to add on Ralfs comments, please note that Aztec/Channel5 still may have the issue that it displays the polefigures (or ipdf colorcoding) not necessarily in the same coordinate system as the map/your sample. 180° around the Z was quite often observed, but also 90° seem to be quite common. this means getting your mtex result to coincide with Aztec may not necessarily mean that you'll get an absolute orientation - if that matters.

There's something more on that here: https://groups.google.com/d/msg/mtexmail/EpOQo04KsmM/ugvOYTOqBgAJ for example.

Cheers,
Rüdiger