I am observing the dendrite deformation in Ni-based single crystal investment casting. The cruved growth trace of the dendrite arm was found, and the misorientation profile (relative to the first point) along this growth trace was also obtained. However, I have no idea to how to obtain the correspongding bending angle and the rotation angle in EBSD analysis.
Thank You
Are you sure this is not an effect of the misalignment of the sample? It looks more like an incorrect pattern center adaptation to me.
Anyway, if I download the image there is no scale visible. The entire background is black. I guess it is set to transparent and then white is black and black is black as well...:-(. If this is the misorientation angle then this describes the misorientation angle already. If you want the misorientation to the previous pixel you can certainly click a check box.
The misorientation matrix is derived from the multiplication of the orientation matrix of point A with the inverse of point B. The trace of the matrix gives you the misorientation angle and all mixed elements determine the rotation vector.
There are several ways to solve this problem, e.g. the texture book of Engler and Randle contains this formula. But it is also pert of many publications. You can alternatively use MTEX, a free software.
However, I personally believe that the observed effect is an artifact of your experiment and not real. In order to avoid this you need to prepare your sample exactly parallel, i.e. at the beginning grind back and front side parallel and take care that you also mount the sample with the front side parallel to the X-Y plane of your stage. Or do you use a pre-tilted sample holder?
Dear Gert, thanks for your opinion. This is not an effect of the misalignment of the sample.I think I should supplement the background: the dendrite microstructure in the picture was located on the platform base, and the platform base and platform top is parallel, which has been ensured by the wire electro discharge machining (EDM).
The curved dendrite growth trace is marked by the red dotted box. In OIM (orientation image map), I could obtain the misorientation profile along the growth trace. However, the dendrite arm not only become curved in the X-Y plane (the rotation phenomena), but also curved in the plane perpendicular to the X-Y plane (the bending phenomena).
Besides the misorientaiton profile, the rotation misorientation profile (misorientation between measured points and the first point in X, Y axis) and the bending misorientation profile (misorientation between measured points and the first point in Z axis) are also what I want to obtain. However, I could not acquire these informations in the ready EBSD analysis.
I understand. This is certainly possible with MTEX since MTEX does not only display the misorientation angle but also enables the display of the misorientation axis. I believe that this is also possible in OIM. Unfortunately, I do not have OIM, however, MTEX is a very powerful tool as well and free available if you have Matlab. In MTEX you can display the local orientation with respect to the average orientation and possibly also with respect to any predefined orientation. This enables a nice characterization of orientations, cf. fig 13 f and g. The resolution becomes even better in h) but this is then again more quantitatively...
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science