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The results indicated, in Nb-40Ti-15Al alloy, the solidified Structure was typical small equiaxed grains, columnar crystals and common equiaxed crystals.
As for Nb-40Ti-10Cr-10Al alloy, the addition of Al and Cr lead to a great number of sub boundary and precipitated phase, and the microsegregation in alloy are also reduced to a certain degree.
At triple junctions of adjacent grains, the angles of two grain boundaries are almost at 120°.It indicates that the neighbor grains own the same interface energy, hence a homogeneous single-phase alloy.
Following the ASTM standard E112, the grain size was calculated to be 250 μm-300 µm.
The difference is the clearly and densely sub-grain boundaries.

Grain boundary sliding - the principal deformation mechanism operating during superplastic deformation - occurs at high-angle grain boundaries only [11], which makes the character of grain boundaries an important parameter with great influence on superplastic properties.
The average grain size is below 1 µm and a large part of the grain boundaries are ill-defined.
For the calculation of this value, only entities separated by grain boundaries with a misorientation of 10° or more were considered as grains.
The average grain size after the pressing was 0.6 µm. 2.
Acknowledgements This work was supported by the research project 1M 2560471601 "Eco-Centre for Applied Research of Non-ferrous Metals", financed by the Ministry of Education, Youth and Sports of the Czech Republic, as well as grant number 106/07/0303 of the Grant Agency of the Czech Republic.

From the point of pinning factor on the grain boundaries, the fine grains impede domain wall motion in the magnetization process.
This increase is indicated that the primary effect of secondary phase formation on the grain boundaries is to suppress the grain growth and limit grain-boundary mobility during sintering [12].
This results in refinement of grains, with a reduced number of inner pores.
With increasing the number of Fe3+ substituted by Sm3+, Fe3+ content decreases and effectively restrains the transition from Fe3+ to Fe2+ in ferrites.
On the other hand, small grains are preferred as oxidation advances faster in smaller grains and the probability of Fe2+ formation in smaller grains is low[16].

Introduction The morphology of primary phase in semisolid alloys is important for a number of reasons [1].
It is seen from Fig. 1 that there is a number of primary phase with rosette-like and a few of dendritic grains when isothermally held at 5800C.
The primary phase presents the changing tendency: dendritic crystal→rosette grain→approximate globular grain→globular grain with the increase of holding time.
Logarithm is taken for the size and number of the box, then data is drawn in bi-logarithm coordinate to make an analysis for linear regression.
The smaller fractal dimension expresses that microstructural morphology is simple and regular, and roundness of grain is better.

This type of network can have considerable number of layers, where each layer capable learning to recognize different features of an image [7].
This has 34 layers (convolutional layers), each layer has a certain number of filters to recognize features using discrete transformations.
For example, if a list with two object classes [grain, not_grain] is created, the object class grain (grain) is assigned a greyscale value of 0 and the object class not_grain (no grain/grain boundary) is assigned a greyscale value of 1.
The number of images depends on the complexity of the image structure.
For that reference image, 80 is a solid number for obtaining basic results.

The crystal grains of the steel wires grew significantly after brazing.
For these two kinds of bond materials, diamond grains are bonded mechanically by the bond materials.
As a result, diamond grains are easily pulled out during cutting and these diamond grains then participate in cutting process as loose abrasive, which results in low workpiece quality and material wastes.
The average diameter of diamond grains is 100 µm (140/170 US mesh).
As compared with other materials, diamond grains worn most severely while cut ceramics.

The average grain size and the standard deviation were calculated from measurements of 20 grains for each microstructure.
This seem to indicate that while for the green densities (A) and (B) the distance among some particles and/or agglomerates is large and, hence, the particle/agglomerates number coordinated by a pore is high (Fig.1A), for high green densities (C) most of the pores have dimensions comparable with the grain size (Fig.1B) and consequently, a lower particle coordination number.
If the grain-boundary migration is rapid, it can, for a certain green density, trap the pores in the cores of the grains as shown in Fig. 3 B1 and B2.
This will therefore alternate conventional grain growth to porous body grain growth.
As new contacts between growing grains occur, less faceted grains are created (Fig. 3 B1 and B2).

In most cases the process is used for grain size refinement.
In order to add homogeneity in the distribution and size of grains the material is subsequently heat treated.
However, large initial strain is achievable in a small number of cycles.
For example, grain size was shown to decrease with the increasing numbers of extrusions passes applied to a billet [2,3].
As a consequence, it was also shown that, with the evolution of grain refinement and subsequent increase in mechanical properties the measured tool forces increased with the number of passes, despite there was no change in the material geometry [4].

In a previous study [3], we have applied the technique to as-deposited CrN and TiN coatings and could obtain strain vs. sin2ψ distributions range for a number of (hkl) planes.
Each grain is only surrounded by other grains in two dimensions and the grain interaction in the direction normal to the coating is expected to be weak.
The stress tensors are represented by a spherical harmonic function expressed in a limited number of series coefficients, which may be directly determined from the measured lattice strains.
The residual stresses are still found to vary with different sub-set of grains.
Such interactions can be selective, namely varying with the coating direction and grain orientation, and are not described by any existing grain interaction models.

In general, the number of white-bright zones and segregation is increasing with the increasing in the content of Mn, but the impact toughness is decreased.
As a result of manganese precipitation at grain boundaries, principally grain boundary martensite is formed.
After prolonged austempering this grain boundary martensite disappears; however, the precipitation zones resist the bainitic transformation and non-transformed grain boundary austenite is preserved [10].
The amount of martensite has a little increase in the grain boundary.
The lump-like carbide distributes in the grain boundary thus the number of white and bright zone increases obviously and results in the reduction of toughness.