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The results showed that with decreasing grain size the number of twin annealing added And four types of annealing twin in the microstructure, in the end they all become one twin and then turn into grain.
Twin boundaries act like grain boundaries.
On grain boundaries there are {111} plates.
Some important factors affect the rate of twins formation during grain growth including: rate of deformation before annealing, temperature and time cycle of annealing heat treatment, grain size, energy of grain boundaries, migration velocity of grain boundaries, SFE, context of grains and impurities [4].
A stands for corner twins, B stands for a given type of twins connecting both ends of a grain to each other, C stands for a given type of twins restricted within grains and D stands for twins restricted within grains but inclined towards grain boundaries.

Grain refinement is expected to promote significant enhancement in both properties.
This number is expected to double between 1999 and 2025 as a result of aging populations worldwide and growing demand for a higher quality of life. [9] Another statistical data estimated that by the end of 2030, the number of total knee arthoplasties is predicted to grow by 673% from the present rate [10].
Achieved by optimizing grain flow characteristics during forging process, the ability to tailor this directional strength permits forgings to meet different performance requirements for an almost unlimited number of part configurations [8].
A representative bright-field TEM image of the grain structure of CoCrMo alloy is shown in Figure 3 (a).
The forging step done only once and resulted in positive findings on the grain structure of the alloy.

The tetragonal grain size decreases with increased amounts of alumina.
Usually, the cell parameters start to increase with a grain size below 30 nm [22,23].
Initial calculation of the attractive potential for a one dimension ion arrangement, as a final segment, shows that there is a sharp decrease in the attractive potential, when the number of pairs is below 100 (See Fig. 8). 0.50 0.55 0.60 0.65 0.70 1 10 100 1000 10000 2N (N is number of pairs) Factor Fig. 8: Half of Madelung constant as a function of number of cation/anion pairs for a line of alternating cations and ions.
For an infinite number of pairs this number is ln2.
The gradual transitions versus grain size can be attributed to non-uniform grain size.

The diameter of a crystal grain of AZ31B-430 is larger than that of AZ31 B-O.
The diameter of a crystal grain of AZ31B-200 is larger than that of AZ31 B-O.
The diameter of a crystal grain of AZ31B-430 is much larger than that of AZ31 B-O, and the form of a crystal grain also changes.
The number of load cycles, which generates a crack from an initial-crack tip, is shown in Table 3.
We define the number of load cycles when half crack length exceeds 10μ m as the crack generating number of load cycles.

The grain boundary is ambiguous, and α-phase grain occur fusion, merger and adhesion.
At this time, the grain growth mechanism becomes Ostald growing up, that means large grain grows, and small grain gradually decreases even melts.
And the grain boundary is relatively clear, with a fine grain size of an average diameter of 48.3um.
When the isothermal holding time is 10min (Fig.3b), grain size and morphology have taken place great changes, some small grains melt away, other grains combine each other and grow up, and the grains are round, with the average size of 58.1um.
It can be seen from above comprehensive analysis that during the initial stage of isothermal holding, the grains grow faster, with time goes on, grain growing speed slows down, and the number of small grains reduces, the grain size also becomes smaller and smaller or even completely melted.

When analyzed grinding process, Tönshoff et al. further studied undeformed chip thickness model after describing the three-dimensional and two-dimensional appearance of a large number of grinding chips[2].
In this paper, the grits are assumed to be perfectly conic, the grain diameter is normally distributed, and the spatial distribution of the grains is uniform in the wheel volume.
Suppose is the number of the grits simultaneously participated in the work on unit width contact arc length ，then .
In the experiments, the dimensions of the workpiece is 24mm*12mm*6mm, of which the material is steel 55. 3.1 Measurement of the inter-grain spacing The inter-grain spacing is one of the most important parameters in the analysis of grinding forces.
After calculation in Matlab7.1，the average inter-grain spacing of the CBN grinding wheel is obtained as：.

The article deals with comparison the influence of traditional ball mill with high-speed shredder on shape and size of grains.
This type of mill uses exchangeable grinding rotors for achievement of big specific surfaces and treatment of grain morphology.
It was chosen the number of material passing in desintegrator.
The number of particles considerably decreased by size 100 to 1000 μm in comparison with commercial produced cement.
Registration number CZ.1.07/2.3.00/20.0111.

A large number of liquid phases are emerged and discrete solid grains are produced by increasing the soaking time.
It has been proved that the coalescence frequency is proportional to the number of adjacent grains.
The intragranular droplets in the primary grains will also grow by reducing the size and number with increasing heating temperature and holding time.
Coalescence occurs when the adjacent grains combine into a larger grain.
The coalescence frequency is associated to the number of the grains connecting with each other.

The results indicate that LAGB's change to HAGB's as the increase of number of process.
The average grain size, aspect ratio of grains and fraction of HAGB's are shown in Table 1.
Aspect ratio of grains didn't change after aging treatment while grain size increased from 210 to 240 nm.
58 0.22 ARB/3cycles 300nm 0.4 58 0.22 ARB/3cycles 300nm Number of ARB cycle Vickers hardness, Hv 140 150 160 170 180 01 3 5 Number of ARB cycle Vickers hardness, Hv 140 150 160 170 180 01 3 5 why grain growth doesn't take place so much will be due to precipitates disturb the grain boundary migration effectively.
On the other hand, in ARB/aged ones, (c) precipitation hardening may be so effective, (d) bonding defects may disappear or decrease in number due to aging treatment.

Figure 2 Microstructures of the samples under different deformation temperatures (a) 900℃ (b) 950℃ (c) 1000℃ (d) 1050℃ (e)1100℃ As shown in figure 2, under the same strain rates and deformation dimensions, when the deformation temperature was 900°C, a large number of deformed austenitic grains appeared at the core-area of the sample, and a small amount of recrystal grains also appeared.
When the deformation temperature was 950°C, the number of small recrystal grains increased obviously.
Figure3 Microstructures of the samples under different strain rates (a) =1s-1 (b) =0.1s-1 (c) =0.05s-1 (d)=0.01s-1 As shown in figure 3, under the same deformation temperatures and deformation dimensions, when the strain rate was 1s-1, a large number of deformed austenite appeared at the core-area of the sample, and a small amount of recrystal grains also appeared, the grains’ size were 5~10mm.
When the strain rate was 0.1 s-1, the number of the recrystal grains increased, and the size of the grains also increased.
When the strain rate was 0.05 s-1, the recrystallization was almost completed, and the grains’ size was also uniform, about 20mm, a small number of deformed grains still existed.