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Three different measurements with a different number of slices were carried out on one sample and the parameters are given in Table 1.
Measurement X (TD), [µm] Y (ND), [µm] Z (RD), [µm] Number of slices Volume, [µm³] 1 16 14 6.2 62 1388.8 2 15 10 6.5 65 975.0 3 15 10 2.7 27 405,0 Table1.
The grain shape of each individual grain from the examined volume was approximated with an ellipsoid.
After applying both cleaning methods, the total number of grains remaining from the three scans was 615.
(d) Quantitative description of the grains volume fraction as a function of the grains major axis with respect to the sample rolling direction.

Introduction The attractive application potential of the materials with nanometer-sized grains is anticipated from a high fraction of grain boundaries (GBs) and triple junctions (TJs) between grains in these materials.
In spite of a considerable progress in our understanding of diffusion in nano-crystalline materials, a number of fundamental problem remains still unresolved: to which extent do GBs in nanocrystalline materials differ from the relaxed boundaries in coarse grained materials and to which extent are the various types of grain boundaries in a the same material different; what is the relation between the GB structure and the corresponding energetic and kinetic properties; could one apply the concept of an 'averaged grain boundary' in a nanomaterial; what is the effect of the production route?
One can conclude that in the nanocrystalline material (the grain size d ~ 100 nm) the GB structure is well relaxed and is similar to that in the coarse-grained material.
The grain size after SPD lies typically in the range of about 150 to 350 nm, although a considerably smaller grain size could be reached, too [31].
As a result, a gradient microstructure is produced which evolves from a nano-scaled layer to ultra fine grained, fine grained and finally to the coarse grained matrix.

The average grain size of the composites decreased from 110.35μm to 52.07μm when the TiB2 particles is 4.47%, and the grain size changed slightly when TiB2 content increased further.
Grain size and hardness of the as-aged composites Number 1# 2# 3# 4# Grain size (μm) 110.35 52.07 51.41 51.94 Hardness (HB) 189 197 202 206 Fig. 1a to 1d showed the microstructure of the casting composite with different TiB2 content.
The grain size of the four composites with different TiB2 content are shown in the Fig. 1e black line which correspond with the Grain size in Table 2.
The average grain size of the composites decreased from 110.35μm to 52.07μm when the TiB2 particles is 4.47%, and the grain size changed slightly when TiB2 content increased further.
Because of the difference of thermal expansion coefficient of TiB2 particles and matrix, a large number of additional dislocations were produced around the TiB2 particles, which resulted in hardness increased greatly.

The results can be characterized as that a large number of supersaturated Si elements precipitated from α-Al phase during the process of sintering.
From Fig. 5, slight grain growth can be observed in the microstructure of the sintered compact, but the grain sizes still remain nano size.
The amount of segregated primary silicon grains and the grain size increases, but the average grain sizes still keep submicron size (Fig. 5b, c).
The amount of segregated primary silicon grains and the grain size increases, but the average grain sizes are still submicron size.
In the sintering process of alloy power, a large number of supersaturated solidification silicon elements precipitation from α-Al phase distributed homogeneously in matrix

As the creep mechanism, all tests show grain boundary diffusion or Coble creep is the dominate deformation mechanism, except at higher temperature 750 ºC and higher stress levels.
Under this circumstance, creep failure is diffused by grain boundaries and the minimum creep rate is determined by the following equation [3-7]: (2) where K is a constant (μm-4/mol), Dgb is the grain boundary self-diffusion coefficient (μm3/s), δ is the width of grain boundary (μm), Ω is the atomic volume (μm3), s is the applied stress (N/μm2), d is the grain size (μm), R = 8.314 J/mol K, and T is the testing temperature (K).
Measured grain sizes of 409L and 436 are 18 and 14 μm, respectively; the width of grain boundary is 3 μm for both stainless steels.
Grain boundary diffusional mechanism is the main creep deformation mechanism at 600ºC and at the lower stress levels of 750ºC. 3.
Acknowledgements This work was supported by the Industrial Technology Development Program, Ministry of Economic Affairs of Taiwan under grant number 100-EC-17-A-16-I1-0025 to Yieh United Steel Corporation (YUSCO).

Micrographs of the particle distribution on surface of micro grinding tools Through the investigation and dimension measurement to different size of micro grinding tool, the distribution of CBN grains on the surface of the substrate could be accomplished and it could be described by G0 which stands for number of grains within 1 mm2 of square on surface of the substrate.
Fig. 6 shows the surface of work piece in micro grinding view by microscope, tool is 500 μm diameter, Fig. 6(a) is F800# grain particle size, Fig. 6(b) is F1200# grain particle size, Fig. 6(c) is F3000# grain particle size.
Fig. 7(a) is F800# grain particle size, measure range is 60 μm×60 μm.
Fig. 7(b) is F3000# grain particle size, measure range is 30 μm×30 μm.
From the result it is concluded that large number of grains could turn to low Ra, the F3000# particle size reach a roughness of 0.086 μm.

The improving effect of rubber powder is better than rubber grain.
The biggest grain size of rubber powder is 0.28mm and the biggest grain size of rubber particle is 3~4 mm in diameter.
Fig. 1 indicates that c Relative dynamic elasticity modulus P appears to gradually decrease with increasing freezing and thawing cycle number.
The maximum freezing and thawing cycle number reaches 150.
But too much rubber content results in decreasing frost resistance and can make relative dynamic elasticity modulus rapid decline with number of freezing and thawing cycles

Best crystallinity obtained at 1400ºC sintering temperature of 78.18% due to the growing number of crystals formed by the arrangement of atoms in the sample and more regular.
Furthermore perfecting similar crystalline formation, increasing the grain size, and the narrowing of grain boundaries were occurred [12].
Enlarged impact on the grain size reduced electron scattering, which leads to increased electrical conductivity [13] and the growing grains will increase the electrical conductivity due to the increasing number of electrons that can flow more easily pass through the grain boundaries [11].
Enlarged grain size resulted fewer grain boundaries and increased mobility [10, 14].
The ZnAl2O4 phase to electrons scattering centers, separating the crystal grains and grain boundary area becomes large.

The described process of calculation is used by microstructures of particular planes: · addition of points of intersection boundaries of area orientated grain boundaries of microstructure with parallel (horizontal) experimental lines labeled as (Pp), in the case of microstructure Fig.4, where the number of points of intersection is 491; · addition of points of intersection boundaries of area orientated grain boundaries of microstructure with vertical experimental lines (P0) is 391; · calculation of points of intersection of surface grains with parallel experimental lines related to the length unit of an experimental line (Pl)p with the unit [mm'1] according to the relation · calculation of points of boundary intersection of surface grains with parallel experimental lines related to the length unit of the experimental line (PL)O with the unit [mm-1] according to a relation.
When the value of microstructure orientation is equal to 1 and the number of cross-sections of surface grain boundaries with parallel and vertical experimental lines is same, it means the structure is not orientated.
Orientation of grain boundaries - the _ first draw 057 x 5 mm.
Orientation of grain boundaries - the second draw 050 x 3.75 mm.
Orientation of grain boundaries - the third draw 044 x 3 mm.

TiAl-based alloys are sensitive to its grain structure.
Peritectic reaction grain generated directly from the liquid phase and it is often coarse-grained.
The initial nucleation of β phase exist within the grain.
Fine-grained TiAl alloy solidification due to the quality control of the refractory alloy by adding the number and different types vary greatly. tungsten Is the high melting point and heavy metals, but also a strong β-phase stabilizing element [11-13].
Conclusions If a large number of peritectic reaction occurs in the solidification, the grain size gradually increase the grain size gradually increase and the mechanical properties is significantly worse.