168 Prakt. Met. Sonderband 52 (2018)
shown in a schematic drawing of the indent and its 180°-rotation in Figure 4a. The schematic
indent without rotation is shown in Figure 4b, where parallel deformation lines are visible, i»
which intersect each other at angles between about 52°-58°. J
Wang et al. [8] explained the formation of the two-fold symmetric pattern by the material -
displacement, which occurs out-of-plane and along the zone-axis of the primary (111)-slip
planes and the indented (011)-surface plane and gave the angle between the [100]- and
the [211]-direction on a (011)-oriented surface with 35.3°. The angles measured in this study
range between about 52°-58°, which is in good agreement with the angle between the [101}-
and the [121]-direction (Figure 5a), when it is taken into account, that the specimen surface
is not perfectly horizontal and the grain not ideally in (101)-orientation (10° tilt angle). The
good agreement of the angles between the [101]- and the [121]-direction can be seen
graphically in Figure 5b, where an overlay of the directions on the deformation structure is
shown.
Summing up the results gained from the deformation structure and the EBSD analysis, it is
concluded that the deformation in the alloy in the (101)-orientation is governed by dislocation
slip. The governing deformation mechanisms of grains with (001)- and (111)-orientation
needs to be investigated in further experiments.
gE
1, SUM
(a) (b) oe
Figure 4. (a) Two-fold symmetry observed by rotating a schematic drawing of indent and
deformation pattern (grey) by 180° (red), (b) angles between deformation lines ranging
between about 52°-58°.
i"
(101)-plane
121] a
ha
y 1010] x
x. la 423) or
0 [121] vr
—e is r N
101] DS
(a) (b)
Figure 5: (a) Observed out-of-plane material displacement profile on an (101)-oriented
surface plane showing the angle of 35.3° between the [010]- and the [121]-direction and
54.7° between the [121]-direction and [101]-direction for slip on the (111)-plane;
(b) overlay of the directions and angles on the schematic deformation structure pattern.