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The average as-deposited copper grain size was 5 µm.
Grain boundary slipping and the dislocation movement coordinating grain boundaries spur the grains rotation and translation.
As the sizes and shapes of grains are diversiform and the dislocation phase within the grain are irregular, , contact stress with oscillating character among the rotating-translating grains are excitated on the contiguous grain boundaries, and the dislocations arise too.
TRV-I TRV-II Fig.6 Schematic diagram of the interacting between two adjacent vortexes →o active dislocation sources →× potential dislocation sources As the vortexes include different number of grains, the grains sizes and shapes also affect the volume and space-time character of vortexes.
In this mechanism, grain boundary slipping and the dislocation movement spur grains rotation and translation.

To increase the strength of cement stone it is necessary to reduce the number and size in the microstructure of the coarse blocks of the portlandite, hydroaluminate, hydrosulphuret of calcium and to increase the number of microfine components, which is achieved by reduction of water-cement ratio and compact distribution of output cementing grains in the system “cement-water” through the use of modifiers.
The test sample is characterized by a fairly dense microstructure with a large number of pores, which are either already overgrown with hydrate new formations, or are in the stage of overgrowth.
To increase the strength of the cement stone, it is advisable to reduce the number and size of large-crystal blocks of portlandite, which is achieved by reducing the water-cement ratio and compact placement of output grains in the cementing system with hyperplasticizing modifiers.
Technogenic sands as effective filler for fine-grained fibre concrete, Journal of Physics: Conference Series. 1118 (2018) 012020
Vatin, Fine-grained concrete with combined reinforcement by different types of fibers, MATEC Web of Conferences. 245 (2018) 03006

Grain boundary diffusion and grain boundary segregation.
Mechanisms of grain boundary diffusion.
Unfortunately, due to different reasons (the work with the radioactive elements is a health hazard, the radioactive isotopes are expensive, etc.) the number of laboratories employing autoradiography falls and, consequently, the number of results is strongly reduced.
A large number of GB diffusion data has been obtained to date, gathered in different handbooks, such as [4,31] and also in the journal "Defect and Diffusion Data".
Over recent years such data have been taken in a number of systems, particularly for different solutes in Cu [40,41,43] and quite recently in ultra fine grained Cu [42].

The results show the hardness increased in the first turn of HPT and further increased with increasing numbers of turns.
The total numbers of rotations were ¼, ½, ¾, 1, 2 and 5.
Similarly, the Si particle size decreased as the number of HPT turns increased, as shown in Fig.2.
Second, the hardness increases with the number of HPT turns.
It is apparent that both the YS and the UTS increase as the number of HPT turns is increased.

Abrasive grain shape is difficult to define.
Obtained an irregular geometry of abrasive grains.
The next step was to designate the top of abrasive grain, and then the actual interpolation curves radially from the top of the grain using the user-selected number of lines (Fig. 3).
In addition, one can observe that the most cutting surface has a grain ZA, and the smallest grain ZE.
Steel Research International Special Edition, Volume 81, Number 9, Publishing Company Verlag Stahleisen GmbH ISBN 978 – 3 –514 – 00774 –1, 2010, pp. 1482 –1485.

From these results, it was known that contact stiffness depended on the number of abrasive grains existing on wheel surface occurred by the difference of dressing lead.
It is considered that this different tendency of contact stiffness depends on the number of contacting abrasive grain acting to the workpiece.
On the other hand, in measurement for the stationary state shown Figure 7, since the number of contacting abrasive grains to workpiece increases with the increase of the contact force as shown Figure 9, the number of the linear spring as the stiffness of one abrasive grain and/or bond increases.
From this calculated result, it can be regarded that the number of contacting abrasive grain existing on the grinding wheel surface is constant irrespective of the increase and/or the decrease of the table feed rate.
That is, since the stiffness of one abrasive grains is constant to against the different grinding force as shown Figure 8, and the number of contacting abrasive grain under the grinding operation for same wheel depth of cut doesn't vary as shown Figure 9, it is regarded that the stiffness of grinding wheel itself under the grinding operation also is constant for the different grinding force.

The grain size of hcp matrix was about 1µm, indicating that remarkable grain refinement was occurred by extrusion since the grain size of as-cast alloy was about 500µm.
Special attention has been paid on the enrichment of solutes at stacking faults and grain boundaries in the fine-grained matrix, which would contribute not only to the strengthening but also to the stability of fine-grained structure because of its role of an inhibiter against grain coarsening.
In the case of Mg alloy, in addition to this contribution, ductility is improved by grain-refinement because of the increase of the number of independent slip systems activated.
The extruded alloy consisted of the dispersed block of LPSO phase and the fine-grained matrix with the grain size around 1 µm.
HAADF-STEM images exhibited that Zn or Y were enriched at grain boundaries and stacking faults inside the grains in the matrix, which would increase the thermal stability of the fine-grained structure.

The effective diffusivities derived from both sections are more than 2 orders of magnitudes higher than the grain boundary diffusivities in coarse-grained Cu.
Recently, investigations on the diffusion in an ultrafine-grained Cu-Zr alloy produced by equal channel angular pressing (ECAP) showed two kinds of short-circuit diffusion paths: one was associated with the "non-equilibrium" GBs containing a large number of dislocations and defects and the other one corresponded to the relaxed high-angle GBs (HAGBs) [3].
The variation of the grain/cell size with the depth is summarized in Fig. 1(b).
As described previously, NS grains in the top surface layer are formed by the "cutting" of nanometer-thick twin-matrix lamellae by dislocations and a large number of interfaces in the top surface layer are expected to originate from TBs.
In the top layer of ~10 m in thickness, the grain size is in the range of 10-25 nm and a large number of interfaces are developed from TBs.

The Grain Boundary Wetting in the Sn- 25 at% In Alloys C.
The grain boundary (GB) wetting was investigated in the Sn - 25 at.% In alloy.
Figure 1 A grain boundary (GB) and two adjacent grains in equilibrium contact with a liquid phase L and the dihedral angle θ. θ > 0 because 2σSL ≥ σGB Figure 2 GB energy σGB and interphase boundary energy σSL decrease with increasing temperature.
The grain size of these specimens was approximately 200 µm.
If the In atoms in grains of 25% In reveal about 400 counts (Fig. 6a), the average number of 800 counts in the GB region corresponds to the equalmolar of Sn and In in GBs.

Fig.4 shows clearly the abrupt increase of visible ferrite grain number via time due to straining.
However, even a small strain can lead to an increase of ferrite grain number and decrease of ferrite grain size (Fig.5b).
Due to the very limited un-transformed region or strong recovery of ferrite the ferrite grain number can not increase significantly.
However, the dynamic recrystallization of ferrite may lead to an apparent increase of ferrite grain number and further reduction of grain size.
Note that in spite of these two unfavorite factors for ferrite nucleation the dynamic recrystallization of ferrite may contribute to a higher grain number.