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In this case, the structural-phase state is considered at three levels: macro (in the size of the magnet, [mm]), micro (in the size of the grains of the main magnetic phase and the intergranular space, [μm]) and "nana" (in the size of fractions of the grain boundary, < 0.01 [μm]) [6].
Within the framework of such approximations it was found that the maximum cooling rate of such (model) grain boundary can be realised along its surface (along the grain boundary body) and reaches up to 1000 K/s (along the radial direction lying in this plane).
n [21, 23, 24] it has been found that for a number of eutectic alloys based on REM, the cooling rate obtained is sufficient for the solidification of the amorphous melt.
This means that they require special analysis of heat and mass transfer during grain recrystallization and magnet sintering.
The functional properties required for an anisotropic sintered magnet are essentially formed during recrystallization of Fe14Nd2B phase grains in the powder matrix, which necessarily contains a certain minimum number of particles of optimal size (≈ 6 μm) formed in the material during mechanical grinding of "MQ GAP" of the used fractional composition (+10, - 640 μm) [6, 19].

Although the morphology of buckles was investigated in a number of works [2-4], there is still a lack of information about defect evolution in buckled films.
The Pd film exhibits nanocrystalline column-like grains having width of ~ 50 nm.
Since positrons are annihilated predominantly from trapped state in open volume defects at grain interfaces, SPIS is sensitive to filling of grain interfaces by hydrogen.
This is in accordance with acoustic emission (AE) measurements which revealed a huge increase in the number of AE events when buckling of Pd film occurred [12].
Subsequently, hydrogen occupies interstitial sites in grain interiors.

By the selection, some individuals that show high fitness in the population are chosen and the others for maintaining the same number of individuals at each generation have to be reproduced.
The grinding parameters considered in this study were specimen having a different Mg content, grain size of wheel, table traverse speed and depth of cut in a pass.
Since the higher variation of the S/N ratio at each parameter had the more effect on grinding outcomes, it was seen that the Mg content at specimen and the grain size of wheel dominantly influenced the surface roughness.
Grain size(#) 46 120 200 C.
Ft η S/N ratio (dB) Fig. 1 Experimental results and calculated S/N ratio A1 A2 A3 1.0 1.5 2.0 2.5 3.0 3.5 4.0 S/N ratio for Ra (dB) Specimen B1 B2 B3 Grain size C1 C2 C3 Table speed D1 D2 D3 Depth of cut A1 A2 A3 -43 -42 -41 -40 -39 -38 -37 S/N ratio for Fn (dB) Specimen B1 B2 B3 Grain size C1 C2 C3 Table speed D1 D2 D3 Depth of cut A1 A2 A3 -36 -35 -34 -33 -32 -31 -30 S/N ratio for Ft (dB) Specimen B1 B2 B3 Grain size C1 C2 C3 Table speed D1 D2 D3 Depth of cut Fig. 2 Effect of grinding parameters on grinding outcomes � � � � � � � � � � Fig. 3 Second-order response surface and contour plot for surface roughness 0.4 0.6 0.8 1.0 0.4 0.6 0.8 1.0 Predicted Surface roughness, Ra(µm) Measured surface roughness, Ra(µm) 40 80 120 160 200 40 80 120 160 200 Predicted normal force, Fn(N) Measured normal force, Fn(N) 20 40 60 80 20 40 60 80 Predicted tangential force,

One of the latest developments is to shrink the size of the metal powder grains.
Microstructure of Cu-Fe after MM The powder is milled with various size of grain.
Figure 2. shows the size of the Cu-Fe powders after MM, it is clearly showed that the grain is finer, the powder size is between 6 μm to 30 μm.
This is because a number of lubricants burnt and evaporate during the sintering process.
The size of the metal powder grain is minimized by means of milling time, from 26 μm to 85 μm to become 6 μm to 30 μm. 2.

Zr is added as a grain refiner [5].
Microstructure consists of homogeneous grains with Zn- and Zr-enriched zones (Fig.1a, 1c, 2).
Cyclic thermal shocks induce appearance of Mg12Nd phase on grain boundaries.
The strict correlation between number of thermal shocks and volume fraction of Mg12Nd phase has not been proved. 4.
Das, Grain refinement of magnesium alloys by zirconium: Formation of equiaxed grains, Scripta Materialia 54 (2006) 881–886

The physical properties of ULWC were estimated by testing bulk density, grain density, 24 h water absorption and expansion rate.
Bulk density, grain density and water absorption were determined according to GB/T 17431.2-1998, China.
This was the key reason for the increase of expansion rate and water absorption and the decrease of bulk density and grain density.
As shown in Fig. 2 (G-a, G-b; I-a, I-b), the number of open pores on the surface of SSC decreased and the abundant developed pores could be observed on the fracture surface.
The water absorption could not change significantly, while the bulk density and grain density became smaller.

The thermo-mechanical processing has also been introduced to refine the grain size and adjust the microstructure3.
Recently，a number of studies have been carried out on high strength steel in China, but most of these studies focus on the yield strength of grade 800 MPa4,6.
High density of dislocations distribute in the bainite grains or at the grain boundaries, resulting in improvement of the steel strength8.
After tempering, the carbide particles smaller than 50nm9 were precipitated in the grains or at the grain boundaries of lath martensite, which are sphericity shape and or spheroidicity shape.
Grain Refinement of V-Ti-N Microalloying Steels through Recrystalization and Contral Cooling.

This process was developed by Segal et al. [1] and has been proved to be very effective in developing ultrafine grain sizes in polycrystalline materials [2-4].
By exposing coarse-grained materials to severe plastic deformation to obtain ultrafine-grained materials, it is essential to study the deformation behavior in the specimen during the process.
Langdon, Equal-channel angular pressing of commercial aluminum alloys: grain refinement, thermal stability and tensile properties, Metallurgical and Materials Transactions A, 31(3) (2000) 691-701
Langdon, Principle of equal-channel angular pressing for the processing of ultra-fine grained materials, Scripta Materialia, 35(2) (1996) 143–146
Langdon, Influence of channel angle on the development of ultrafine grains in equal-channel angular pressing, Acta Materialia, 46(5) (1998) 1589-1599

When the solidification process continues, Cu grains continue to unite to form Cu clusters (as shown by the arrow A).
Few big globules of Cu are found and quite a number of nano-Cu grains (as shown by arrow E) are dispersed in the metal matrix.
Some Fe grains gathered which appear in the matrix (as shown by the arrow F).
So the cooling rate increase, the size of grains become smaller due to the precipitation element has no time to gather.
Lowest coercivity are found for smallest grain size like in amorphous alloys and in nanocrystalline alloys[21].

In general, rational fertilization can increase grain yield and improve the efficiency of the cultivated land output.
CLPSC is reflected the relationship between the single grain yield and applying pesticide.
But only in 2008, there were y>p>0, k3>1 and p maintained in a reasonable range, which was conducive to the improvement of grain yield.
In 2010, there were y1, which indicated decreasing of pesticide use caused the per unit area yield of grain larger reductions.
This illustrated the link between the single grain yield reduction and unreasonable applying pesticide was inevitable.