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INTRODUCTION In describing recrystallization and grain growth it is necessary to know the migration mechanism of grain boundaries.
SINGULAR GRAIN BOUNDARIES Before discussing the grain boundary roughening, it is necessary to define and describe the observations of singular grain boundaries.
The grain boundary energy γg depends on the misorientation angle between the grains and the orientation of the grain boundary plane or the inclination angle θg.
For grain boundaries with low Σ coincidence site lattice (CSL) relationships between the grain pairs, the singular grain boundaries may lie on the planes of high CSL point densities.
Based on the temperature dependence of structure factors, order parameters, layer occupation numbers, and radial distribution functions in three dimensional systems, it was shown that most of the low ∑ boundaries examined showed disordering to liquidlike structures starting at such low temperatures as 0.5Tm.

Grain boundary sliding.
Shear and normal traction acting on a plane boundary with a normal vector can be calculated as follows: (2-1) (2-2) The superscript indicates the number of assumed boundary plane.
It is worth mentioning that assuming a higher number of slide directions than 12 had no significant change in the results, therefore, only 12 slide directions were enough in the present modeling.
Grain interior plasticity.
The numbers of grains P with various diameters in NC materials can usually be well represented by a log-normal distribution function: (39) where d is the grain diameter and and are constant parameters describing the median and shape parameters of the distribution, respectively [26].

Before diamond grain tack-on operation, ultrasonic agitation can make grain dense and guarantee nice contact between substrate and grains.
Diamond grain numbers per unit area were computed as grain density.
Grain Density.
Then in second stage, quick electroplating with high current density can be carried out with application of ultrasonic agitation. 0 5 10 15 20 25 30 No.1 No.2 No.3 No.4 Buildup scheme Grain numbers 0 100 200 300 400 500 Agitation No agitation Tool type Grinding ratio Fig.3 Diamond grain density of tools Fig.4 Grinding ratio Grinding Ratio.
Before diamond grain tack-on operation, ultrasonic agitation can compact grains and guarantee the nice contact between substrate and grains.

Introduction Grain size effects in ferroelectric ceramics is of great importance due to the market demand for small-grain-size ceramics.
The average grain size for each sample was determined using the linear intercept method by counting at least 200 grains in SEM images.
Distinct grains and clear grain boundaries can be clearly observed in the ceramics.
Due to the same reason, the capacitance decrease for coarse grain samples is larger than that of samples with small grain sizes.
The decrease of the saturation polarization Ps with the increase of mechanical uniaxial stress indicates that the number of switchable ferroelectric domains decrease significantly under the uniaxial mechanical stress.

In this case, the main scientific and technological tasks are: 1) to ensure that the recrystallization starts in a large number of centers; 2) to limit the growth of recrystallized grains during superplastic deformation (SPD).
Cold hydrostatic extrusion was used for grain refining.
Dispersoids restrict grain growth during recrystallization.
Grain size was determined in two directions (LL – grain size along the rolling direction, LT - grain size in the transverse direction).
The grain structure of the samples obtained by the second regime consists of finer and more equiaxed grain (Fig. 5 b, Table 3) with the grains form factor about 1.0 – 1.4 (Fig. 5 b).

For example, a number of reports on NC Ni with grain size from 30 nm to 100 nm have been reported [4-6].
And the reason for that is the same numbers of dislocation nucleated from GBs and annihilated at opposite GBs so that the amount of plastic carrier remains roughly the same during plastic flow process.
As a result a large number of stacking faults left in the grain interior (see Fig. 3(a)).
(a) In NC Cu, a large number of partial dislocations connecting with stacking faults are observed in the grains.
Also dislocations and stacking faults are smaller in numbers in the grains.

Meanwhile, the grain size can be further reduced.
A number of studies have already been reported concerning the impact of rotating magnetic fields in solidifying metals [11-14].
The comparison of these photographs demonstrates that complete conversion of coarse columnar grain structure to fine equiaxed grains occurred within 5 min after inoculation with grain refiner Al-5Ti-1B.
When applying RMF to the Al without Al-5Ti-1B until solidification, big columnar grains change into fine equiaxed grains.
In the grain refining practice, TiB2 plays an indirect role in grain nucleation.

The number of the cutting and contacting abrasive grains was calculated.
The statistical research on the number of grains The probability distribution functions about the height of grains.
The number of the smallest abrasive grains and the largest was very small, while the number of adjacent to the average abrasive grains was the most on the surface of grinding wheel.
The number of the grains in grinding arc area.
The number of abrasive grains in contacting and the number of abrasive grains in acting cutting is determined analytically.

The increasing number of coal-fired power plant in Indonesia, then the amount of fly ash waste will also increase. 3.3 million tons is resulted the in 2009[7].
Orthogonal Array (OA) OA selection criteria standards to be used is determined by the number of degrees of freedom (degree of freedom) factors experiments, where the number of experiments on standard OA selected must be greater than or equal to the number of degrees of freedom experimental factors.
The number of degrees of freedom experimental factors calculated by the following eq. 1: The number of DOF = Average number + [number of factors (number of level-1)] (1) Result and Discussion Brinell’s hardness number (HB) is obtained by making a load of 62.5 kg and 2.5 mm diameter indenter.
Grain size is the importance factor that is influence of Aluminum/5% fly ash with sintering temperature 550 oC.
Whereas, more small of grain size can increase of alloy hardness. 3.

Diffusion Controlled Grain Triple Junctions Wetting in Metals B.S.
The number of the filled TJs was determined and shared on their total quantity on the observable area.
Area number one where the melt fills the GBs and TJs both.
And area at number two where the melt fills only TJs of grains.
Randle: The Measurement of Grain Boundary Geometry.