Investigating different iron meteorites I found recently a {011} pole figure which shows the pole distribution in the attached image. It represents the orientations found for the bcc phase kamacite. The displayed pole distribution does not match to the typical models Kurdjumov-Sachs, Nishiyama-Wassermann, Greninger-Trojano, Bain, Pitsch or Headley-Brooks.
Is there anybody who can either tell me, which one is it, or where he/she has seen it?
Dear Gert:
The OR seems different from conventional ORs for fcc and bcc system. A rough estimation of OR (error around 5 deg.) according to brown data in your PF, the OR matrix is
-0.32582 -0.68576 0.65082
0.5726 0.40464 0.71302
-0.75231 0.60498 0.26083
The corresponding pole figure is shown in attached file, and (011)fcc is near parallel to (011)bcc.
May be there are multiple ORs. Would you please use distinguishable colors in your PF or separate the data so that I can find the ORs.
Best regards,
Xinfu
Hi Xinfu,
thanks for the fast reply. I also played a bit around with my software and finally gave up. I got similar results like you, but the poles seems to be not splitted.
You are also right, it seems to be that there are at least two OR (the major is (111) twin). But the second I couldn't really fit. Therefore my question: Is there anyone who'he already seen such a "interesting" pole distribution?
Attached is the folded distribution.
Dear Gert:
If we consider the other OR, it is
-0.51307 -0.23231 0.82631
0.6279 0.55479 0.54585
-0.58523 0.7989 -0.13878
When it is superimposed on the previous 011bcc PF, it seems closer to your original data (see attached file).
The common feature is that [011]fcc is nearly paralllel to [011]bcc for both ORs as also clearly shown in your second figure. Such a parallelism remind me a paper on duplex stainless steel. [011]fcc // [011]bcc is also shown in their system (see attached file), but the difference is that the close packed planes are parallel in their system as in K-S, N-W ORs.
As for the deviation from conventional ORs, the possibilities are
(a) the lattice parameters changes
(b) the morphology is largely different from from lenticular or lath shaped
(c) due to thermal history, such as recrystallization etc
Regards,
Xinfu
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