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The factor of hydride orientation (f) is determined (in same way as for zircaloy-4 tube) with the relation: f = Nr/ (Nr + Nl), [5] (1) where: Nr - number of radial orientation hydrides (45-90o); Nl - number of circumferential (axial orientation) hydrides (0-45o).
The recrystallization degree is the ratio between the thickness and the averaged length of the grain.
The shape of the hydride platelets is influenced by the microstructure morphology: For a microstructure with deformed grains (Fig. 1), the hydrides will have a parallel threads (rows) shape (Fig. 2), of different lengths disposed between the lengthened grains.
The shape of the hydride platelets is influenced by morphology: -For a microstructure with deformed grains (fibrous aspect), the hydrides will have a parallel threads (rows) shape, of different lengths, disposed between the lengthened grains.
-For a microstructure with recrystallized grains, the hydrides become branched, having ramifications more and more distant and finer with the increase in recrystallization degree.

The grains are refining.
Along with the increase of the contents of Gd, the number and dimension of β-Mg17A112 phase decrease.
The grains are refined.
It can pin grain boundaries, hinder the growth of grains and refine the grains.
When the grain is finer, there are more grain boundaries.

Concurrent Coupling of Electronic-Density-Functional, Molecular Dynamics, and Coarse-Grained Particles Schemes for Multiscale Simulation of Nanostructured Materials Shuji Ogata 1 and Takahiro Igarashi2 1 Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan; ogata@nitech.ac.jp 2 Japan Science and Technology Agency, 4-1-8 Honmachi, Kawaguchi 332-0012, Japan; t.igarashi@nitech.ac.jp Keywords: density functional theory, molecular dynamics, coarse-grained particles, multiscale simulation, hybrid simulation Abstract.
The coarse-grained particles (CG) method originally proposed by Rudd and Broughton [Phys.
Nanostructured materials with engineering interests involve billions or larger numbers of atoms.
Development of Multiscale Simulation Methods and Their Hybridization Coarse-Grained Particles Method.
Rudd and Broughton [4] proposed the coarse-grained (CG) molecular dynamics method for continuum description of materials.

The uniform grain structure, which consists of β-phase grains with the minimum of elastic modulus, is formed in the alloy ingot.
This structure of grains is typical for α'-phase [4].
Therefore we can assume that this is also the grain of α'-phase.
Besides, there is also a small number of α'-phase (large needles) [4].
Thus, it is determined that a uniform grain structure comprising grains of the β-phase forms in the ingot of alloy Ti-40 mass.% Nb.

The results indicate that SiC particles are distributed along grain boundaries, limiting grain growth and conducing to the refinement of the matrix.
Magnesium and its alloys have lowest density, good castability, high specific strength compared to all metallic constructional materials, a growing number of applications can be found in the automotive sector [1,2].
A large number of methods have been carried out on particle-reinforced magnesium matrix composites.
It can be observed that matrix alloy has been significantly grain-refined by the incorporation of the SiC particles
The grain refining efficiency of SiC in Mg-5wt.

The number of pulses above a given potential threshold (COUNTS) is related to the Barkhausen jumps in the area of the measurement.
During annealing up to 700oC, the alloy enters the two-phase region a+Fe3C and a small number of carbons is removed from the supersaturation ferrite and forms small quantities of cementite at the grain boundaries (tertiary cementite).
Before thermal treatment, the sample grains are inhomogeneous and uneven.
After annealing, the grains become polyhedral and the grain size distribution is considerably narrower leading to a more homogeneous texture.
This is more evident in the grains along the easy axis (`lower level` grains are more resposive to Nital etching).

With the increase of pouring temperature, the average equivalent grain diameter of the primary phase grains in the semi-solid slurry increases gradually, but the shape factor decreases gradually.
Comparing the two kinds of serpentine channel, it is found that the copper serpentine channel can make the primary grains finer, and the average equivalent grain size was 63 μm.
D=i=1N4AπN (1) Fs=Ni=1NP24Aπ (2) where D, Fs, A, N and P are the average equivalent grain diameter, shape factor, area, number of grains and perimeter of the primary α-Al grains, respectively.
With the subsequent melt scouring, most of the primary grains flow away with the melt, while a part of the grains remain and accumulate on the inner wall surface.
Finally, these grains form a residual solidified shell.

The theoretical density, ρx of the resulting material was calculated using (2) [7]: XRD density, ρx= 8MNa3, (2) where M is the molecular weight, N is the Avogadro’s number and a is the lattice constant.
The sintering of the polycrystalline materials influenced the grain size, shape and crystallization.
The reason for the increased permeability is likely to be due to the increase of grain size and reduce of porosity, which reduce the anisotropy arising from the demagnetizing fields outside of grains.
At the higher sintering temperature, fewer number of the grain boundaries would be present, with increase grain size causing the existence of very mobile domain walls, thus increasing the permeability value of YIG.
Li, Grain size-dependent diffusion activation energy in nanomaterials, Solid State Communications. 130 (2004) 581-584

It is determined that: - breaking mechanical strength of such circles ensures their safe operation at maximum operating speeds of 30–35 m/sec; - the use of high-density polyethylene as a binding substance in cutting wheels is not advisable, due to intensive wear and low cutting power of these tools; - wheels for finish cylindrical grinding on the basis of high-density polyethylene and hollow spherocorundum as abrasive grains in a number of key indicators (cutting power, roughness of machined surfaces) are highly competitive with grinding wheels on a bakelite bond or are comparable to them, and significantly exceed the latter in terms of wear resistance.
The percentage of grains made 62%, no other fillers were added.
Practically similar results on the roughness of surfaces treated with experimental wheels made of different abrasives are explained by the fact that the ESF24 spherocorundum wall thickness of the spheres (which are the cutting elements of such grains) are close to the grain size of 24AF70 white electrocorundum (200 μm).
As the number of passes made increased, the tool continued to grind, the effective cutting power remained stable, and no trueing was required.
The highest wear resistance and cutting power among high-density polyethylene-based wheels are found in tools with hollow spherocorundum as abrasive grains.

In case of the SUS316L powder, such a nano grain structure consists of an equiaxed nano ferrite (c) grains which has transformed from nano austenite (i) grains.
When i grain refinement reaches to its grains size less than approximately 10 nm in diameter, the total grain boundary energy exceeds 1000 Jmol-1, which is required for non diffusion transformation in steels [9].
We have reported recovery of highly dense dislocations at 333 K in the MM treated SUS316L stainless steel powder, and this implies that there exist a huge number of defects such as vacancies [5,6].
Close to those coarse globular c grains in the shell region, nano c"grains are also observed as indicated in Fig.6.
Grain size of the nano c grains is approximately 10 nm, and those nano grains have high angle boundaries as indicated by SADP.