13th International Conference on Fracture June 16–21, 2013, Beijing, China -5- thin lamella (about 200nm). As the distance between layers is smaller than the step size used, the occurrence to indexation of crystallographic planes to these regions was not possible, resulting in dark regions. Another plausible explanation is associated to the material deformation, which can contribute to the accumulation of dislocations at grain boundaries, resulting in the non-indexed regions. In Fig. 5b) there is a grain size distributions quite heterogeneous and the absence of (100) plans. While in Fig.5c) shows the propagated crack region by delamination, the same propagates in the grain boundary, featuring an intergranular fracture mechanism. It is confirmed by separation of grains with [111]||ND and [101]||ND texture components indicated by 1 up to 5 grains, respectively. RD RD ND 1 2 3 4 5 a) b) c) ND ND RD 60µm 10µm Figure 5. Microtexture in the region near the crack delaminated. a) SEM from the scanned region, b) distribution maps of orientation and inverse pole figure c) orientation distribution function (ODF) and pole figures. It is well known that intergranular propagation occurs through high angle boundaries. In this context the Fig. 6 shows the misorientation obtained by EBSD technique from the scanned region (Fig 5b)). For generation of statistical data points only disorientation greater than 2° was considered. It is possible to see at Fig. 6 that approximately 42% of the misorientation angles between adjacent grains are smaller than 10° (low angle boundaries) while the other 58% are distributed randomly between 10° and 110°, indicating a high grain boundary angle. For the generation of pole figures and ODF shown in Fig 5c) was used an orientation map from Fig. 5 b) which provides a better precision in the information due to its higher scanned area. The ODF shown in Fig. 5c) reveals that the orientations have α fiber components. The main components
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