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Introduction With the development of Northwest China inland construction, the number of road and railway construction projects increases gradually, and many routes need to go through Gobi area.
In the loading process, the coarse-grained soil deformation mainly results from the relative movement between adjacent grains and grain rearrangement.
Grain analysis.
In dry state, the coarse grains are surrounded by a large number of fine grains, which are in floc-like aggregations, with random shape, size and geometric features.
Meanwhile, the decreasing coarse grains and increasing fine grains in grain group lead to the re-arrangement and rolling of coarse-grained soil in Gobi region under the force of external load until the balance achieved by internal soil force and external load causing the sudden settlement of coarse-grained soil.

At around 400℃ cube grains penetrated to the thickness, non cube grains being formed.
After final annealing up to 540℃ the number of Laue spots decreased, suggesting that grain growth occurred among TD-rotated cube grains.
Decrease in number of grain are from approximately 20 at 320℃ to 1 at 540℃ for {311} spots.
At 295℃ the number of fine dots in the streaks increased and continuous background in the streaks became more weak than at 290℃.
Upon further annealing, number of dots in the streaks decreased, finally disappeared after final annealing.

With a growing number of passes, the size of subgrains observed at ∆ = 2o is not much dependent on N, whereas the influence of N upon the grain size is much more pronounced at higher values of ∆.
The observed ratios Ev(∆=15 o )/Ev(∆=2 o), i.e. the mean number of subgrains with boundaries mutually disoriented by more than 2 o to the mean number of conventionally defined grains, are between 30÷100 and 10÷30 at N = 2 and 4, resp., and 4 at and 8, 12 (the higher ratios at N = 2, 4 correspond to as pressed material and there is no substantial difference between the as pressed and annealed material after N = 8, 12).
In homogeneous systems of grains and subgrains 0.55 ≤ CV a < 1, in mildly non-homogeneous systems is CV a lower than 2 and higher values are typical for systems with multimodal grain size distributions with a great number of small (sub)grains encircled by or included in extremely large (sub)grains which is the case of the material after N = 2 and partly also after N = 4 (for examples of 3D grain systems see http://fyzika.ft.utb.cz/voronoi/).
They decrease with the growing number N, increase with ∆ and are lower in annealed specimens.
With increasing number of ECAP passes, a pronounced grain refinement takes place and simultaneously also the homogeneity and isotropy of the grain and subgrain structures improve. 2.

While these alloys alone are coarse grained, a dispersion of Ti(N,O) particles achieved a fine-grained microstructure.
The number in each image represents the volume fraction of particles obtained by image analysis.
It should be noted that a small number of equiaxed grains were found in Fe-2at%Ti.
The numbers at the lower right of the images in Fig. 1 indicate the volume fractions of the dark particles obtained from image analysis.
As a result, these oxides are not efficient for grain refinement of the ferrite grains.

When compression percentage is 2%, slip system A3 is active in grain 2, and dislocation patterning starts due to accumulation of dislocation (a) Grain 1 (b) Grain 3 Figure 8 Distributions of crystal orientation Initial loading direction [001] [100] Initial loading direction [001] [100] Figure 7 Distribution of induced grain boundary whose misorientation angle is larger than 10° (a) U/L=1% (b) U/L=10% (c) U/L=40% (d) U/L=65% Figure 6 Distributions of total dislocation density (0µm-2 30000µm-2) 0 10 20 30 40 50 60 0.000 0.010 0.020 0.030 0.040 0.050 Compression percentage [%] Number of grains Slip rate 1 2 3 4 5 6 0 Number of grains Slip rate [s ]-1 0 10 20 30 40 50 60 0.000 0.005 0.010 0.015 0.020 0.025 Compression percentage [%] Slip rate [s ] Number of grains Slip rate 1 2 3 4 5 6 0 Number of grains -1 (a) Ultrafine-grained area A (b) Normal area B Figure 9 Evolution of slip rate and number of grains on the conjugate
When compression percentage reaches 65%, a part of the subgrain wall grows into DDWs remarkably in grain 1 in which a larger number of slip system is active than the other grains.
Figure 9 shows the slip rate of active slip systems and the number of grains induced by deformation for the areas A and B represented by two circles in Fig 1.
In Fig. 9, black lines and gray line show the average of slip rate on each slip system and the number of induced grains, respectively.
While, number of active slip systems is small in grain 3 whose normal directions are almost in the initial triangle.

Microstructural barriers against fatigue crack growth Alain Franz Knorr1,a, Michael Marx1,b 1Institute of Materials Science and Methods, Saarland University, Saarbruecken, Germany aa.knorr@matsci.uni-sb.de, bm.marx@matsci.uni-sb.de Keywords: Fatigue, Small cracks, Grain boundaries, FIB-tomography Abstract Fatigue induced fracture is the number one reason for failure of technical systems.
Sometimes the cracks stop completely for a large number of cycles resulting in an additional number of life time cycles.
Afterwards fatigue crack growth is monitored by replica technique; images of the surface are taken after a constant number of load cycles.
This can be repeated for different crystallographic orientations of the two participating grains, the initial grain and the neighbouring grain.
In fact grain A with the initial notch is surrounded by grain B.

Stress amplitutes were 45, 56, 68 MPa, and all tests were terminated when the number of cycles reached 10000.
Precise observation by SEM revealed that a number of fine cracks initiated transgranularly in the vicinity of the 5.3º(Σ 1) grain boundary.
The number of passing dislocations across the grain boundary could affect the susceptibility to intergranular SCC.
Yamashita et al. [1] pointed out that the number of the passing dislocations increases when the misorientation becomes lower than 15 to 20 degrees.
In addition, dominant mode of transgranular fracture in the small angle boundaries could be attributed to the large number of passing dislocations.

Based on the experimental number, the corresponding austenite grain growth kinetic model was formed.
Since the total grain size is constant, an increase in the average grain size means that some grains in the matrix will disappear.
With the free energy of the grain boundary interface as the driving force, the grain boundary migrates and the grain grows up [9].
The number of fine grains is small, the large grains swallow the small grains, and the austenite grain size increases obviously.
Acknowledgments This work was financially supported by Key R&D plan of Shandong Province in 2019 (item number: 2019JZZY020238).

And then, N(δ) is the minimum number that covers the three-dimensional profile with mesh size δ (δ﹥0).
If there is a fractal nature in this three-dimensional profile, the relationship between N(δ), δ and fractal dimension Ds is given by (1) where c is a constant number.
The topography of PcBN grain after grinding test Based on the above method, the whole topography of PcBN grain selected by microscope is extracted and as shown in Fig.2.
When mesh size is δ=5, from Fig.6, only broad profile of the grain can be observed, and it is difficult to grasp detailed fractures on top surface of the grain.
The reconstruction model clearly expresses the wear topography of the grain

Because only SRXed grains appeared and grew, NGed Cu-Zn alloy shows abnormal grain coarsening.
The grains evolved in the samples MDFed at 77 K contain a larger number and plural variants of annealing twins, while those MDFed at 300 K include lower number of a single variant of twins.
The number of annealing twin increases with increasing strain and/or decreasing MDF temperature.
accelerated grain growth to cause rather coarser grains.
The number and the size of the new grain are larger in the samples with higher density of mechanical twins and grain boundaries.