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The results of a considerable number of such measurements were averaged in view of the variations of angles between the foil plane and the plane in which dislocation exists.
The change of grain sizes (d) at a distance (l) from the sample rotation centre: (1) dislocation free grains; (2) grains containing dislocations; (3) grains with fragments; (4) average grain sizes;  is deformation degree Results and discussion Grain structure after THP.
It is known [3, 8-10] that in submicrolevel polycrystals the grains can be: 1) dislocation free grains; 2) dislocation grains which have a chaotic dislocation structure and 3) grains with dislocation fragmented substructure.
An average grains sizes were measured taking into account volume fraction of each type of grains.
The critical grain size here is the grains size if the dislocations inside the grain body are absent and remain only on their boundaries.

In spite of the large number of papers dedicated to different aspects of SPD-processed aluminum alloys, a little effort has been directed towards elucidating the influence of the combined effect of the deformation mode and second phase particles on the microstructure refinement, and on the influence of ultrafine-grained structures close to large particles on early stages of recrystallization.
At this stage the grain size was 40-60 μm.
(Size depends on the applied number of passes.)
This lead directly to fine grain structure.
As for the recrystallized grains, some preferences in the selection of grain orientations were observed.

The current authors also developed multipass processes where the strain was built up over a number of deformations and were able to significantly reduce the critical strain for UFF formation [6].
The microstructure consisted of fine ferrite grains and carbide particles mainly formed on the ferrite grain boundaries (Fig. 2a).
The interior of the grain is generally deformed through a restricted (a) (b) number of active slip systems leading to the formation of an organized banded structure with a systematic alternation in misorientation across the band width [8].
Figure 2: a) Ultrafine grained structure formed through static transformation for a 0.3C-2Mn-2Si-0.3Mo (%wt) steel. b) TEM image of Ni-30%Fe alloy deformed at 570°C at a strain of 1. b) TEM image showing the formation of bands in grain interior (DB) and cell/subgrain (C) in the vicinity of grain boundary (i.e. dashed line). c) and d) are diffraction pattern of areas close to the grain boundary and grain interior, respectively.
The substructure development in Ni-30Fe model alloy also revealed two distinct substructure characters in the vicinity of grain boundary and grain interior leading to the distinct difference in the grain refinement.

Voronoin method[6,7] is a common method to construct nano-polycrystalline materials: First, a number of points whose Z coordinate are controlled to obey the linear probability density function are randomly generate as the center of the grains,and the distance between grain centers is adjusted to avoid the two grain centers being too close.Then, calling the Voronoin function of MATLAB to generate the grain boundary topology of GNG model.Finally, a C++ script from the literature[8] was developed to fill each grain with the face entered cubic (FCC) copper atom lattice.
The initial positions of crack tips in the three samples are in the grain, along the grain boundary, perpendicular to the grain boundary, respectively.
(4) Figure 2 Schematic diagram of relative crack calculation In the process of tensile deformation, as Fig. 3 shows, a large number of hexagonal close packed (HCP) structures occur in the interior of larger grains and near the crack tip, which reflects the intense dislocation activity and a large number of stacking faults in these two regions.
Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility, J.
Fracture behavior of precracked nano-grained materials with grain size gradients, J.

A number of studies have shown that alloying additions of rare-earth (RE) elements to Mg alloys result in a significant weakening of the basal-type texture [1-3].
Rolled sheets of Mg-RE alloys show a large number of contraction- , secondary twins as well as high activity of pyramidal slip, processes which are seldom observed in pure Mg and conventional Mg alloys, such as the AZ alloys.
An analysis based on the in-grain misorientation degree was employed to evaluate the area fraction of the recrystallized grains.
RD ND grains with an in-grain misorientation smaller than 0.5 ° are supposed to be recrystallized.
The recrystallized grains in the sample annealed for 5 s have an average grain size of 7 ± 2 µm, whereas the average grain size of the sample annealed for 3600 s is 54 ± 19 µm.

The different heights are numbered n, m, etc.
Results Grain orientation - texture.
The drop in the relative efficiency is about 5 % when going from grain A to grain B.
Grain boundaries.
Sub-grain boundaries are not presented.

The Influence of Quenching Baths on Grain Boundary Wetting Transition in Sn-25 at% In alloy C.
The wetting behavior of grain boundaries is affected by temperature, pressure and misorientation of grain boundaries.
However, the influence of quenching baths on liquid state grain boundary wetting is rarely reported.
It is pointed out that a proper quenching bath is necessary for preserving the initial microstructure of grain boundary wetting.
Conclusions The grain boundary wetting behavior of the Sn-25 at.-% In alloy quenched in different baths was investigated.

The samples were lightly polished for 10 to 30 seconds using Buehler 0.02 mm MasterMet® colloidal silica. 2.3 Prior Austenite Grain Size (PAGS) and martensite structure Fig. 1 shows the prior austenite grain size of samples LO_HT1 and LO_HT3.
The refinement of the prior austenite grain size is clear.
Table 2 The value of ratio b0 101 81 80 82 111 97 102 111 Total 889 Average111.1 158 165 167 165 162 147 160 172 Total 1422 Average 177.8 Table 3　The value of b1 in each segment 0 1 2 2 0 1 3 3 Total 12 19 12 17 21 17 19 23 15 Total 143 The number of b0 is the number of simplexes and b1 the number of grains.
Here, the image analysis has been carried out by using the homology method to the austenite grains.
This work was supported by JSPS KAKENHI Grant Number 24654025. 6.

The literature reports a considerable number of research works that deal with grain coarsening phenomenon in FSS welds.
Taguchi's design provides a simple, efficient, and systematic matrices to optimize process parameters by minimizing/maximizing output responses with the minimum number of experiments, considering the high performance of results and the least cost of experiments [16].
Taguchi method is a powerful tool that uses a special design to study the parameter space with small number of experiments through orthogonal arrays [18].
In trial9, the microstructures of the fusion zone (FZ) present a large columnar ferrite number compared to trial 4.
That means that electric current amount passing through coarse grains is higher than that of fine grains of base material.

Its mean grain size was about 86µm.
The sample subjected to 4 ECAP passes consisted of equiaxed grains with a diameter of 0.3 ~ 0.5µm, as shown in Fig. 1(c).
Fig. 1(d) shows that the dislocations partly disappeared inside some of the grains after annealing, but no grain growth was observed.
It was found that the tensile strength of the Al 5052 alloy increased, while its elongation decreased, with increasing number of ECAP passes, due to grain refinement and the continuous increase in the dislocation density[3].
As shown in Fig. 3, the Vickers hardness increased as the number of passes increased.