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Magnetically Controlled Grain Boundary Motion and Grain Growth in Zinc Christoph Günstera, Dmitri A.
Mean grain size, number of grains and fraction of different grain subsets after annealing at 340°C for 90 min as obtained by orientation microscopy (EBSD in a SEM).
Field Total number of grains Subset Mean grain size, µm Number of grains Grain fraction both 82 1285 0.67 0 T 1925 (90°,20°,φ2) 81 656 0.34 (270°,20°,φ2) 83 629 0.33 both 100 1298 0.88 17 T 1471 (90°,20°,φ2) 99 444 0.30 (270°,20°,φ2) 100 854 0.58 The rolling texture with two peaks in the (0002) pole figure measured after 90% reduction is similar to those already reported in literature for low alloyed zinc after high rolling reductions.
The information on the grain microstructure with respect to grain size and number of grains composing different texture components obtained by orientation imaging with EBSD is given in Table 1.
A similar behaviour, i.e. promotion of energetically favorably oriented grains number during magnetic annealing, has been also observed in Ti [8] and Zr [11,12].

However, the process depends on several different parameters, e.g.: the properties of the grain boundaries (energy, mobility); the effect of atoms in solid solution; the number density and shape of second phase particles (dispersoids); the crystallographic texture.
The first publication on computer simulation of grain growth appeared in 1979 [1] and a large number of publications have since appeared.
However, simulations of the shrinkage of a circle (2D) and sphere (3D) have shown considerable statistical fluctuations in the movement of the boundaries [4,5] which may question the validity of this method in systems with a small number of grains or when focus is on the individual grain level.
She compared the kinetics and the quasi-stationary grain size- and side number- distributions obtained by the different models and found pronounced differences.
In the present simulations a reorientation attempt is accepted if, and only if, it lowers the energy of the system, i.e. the reorientation is performed with a probability given by 1 0 ( ) 0 0 if E P E if E ì D £ïïD = í ï D > ïî (2) After each reorientation attempt, the clock time is incremented by (1/NQ) Monte Carlo steps, where N is the number of lattice sites, and Q is the number of allowed indices.

Study of Abrasive Grains for Susceptibility to Electrostatic Field Effect V.S.
A large number of studies show that grain orientation by this method improves the cutting performance of an abrasive paper.
However, despite the numerous advantages of the electrostatic coating method in comparison with the mechanical one, there are a number of disadvantages that do not allow the full use of the capabilities of flexible-backing tools.
As can be seen from the diagram, three grain sizes 20, 40 and 16 in decreasing order are most susceptible to the effect of an electrostatic field. 40% of the total mass of 20 grit grains, 25% of 40 grit grains and 15% of 16 grit grains have reached the cathode.
Conclusion The technological parameters of applying top working layers of abrasive paper with controlled orientation of abrasive grains by an electrostatic field include the following characteristics: – output voltage of high voltage source; – abrasive grain applying distance; – abrasive grain grade; – abrasive grain size.

For instance, the use of high-strength bolts can decrease the number, size and weight of bolts used in a car, thereby decreasing fuel consumption.
The use of high-strength bolts can decrease the number, size and weight of bolts used in a car, thereby decreasing fuel consumption.
During normal grain growth (sometimes called "continuous grain growth"), the distribution of grain sizes remains approximately constant and the grains increase their diameter continuously and gradually, displaying a monomodal grain size distribution.
During abnormal grain growth or secondary recrystallization (sometimes called "discontinuous grain growth"), particular grains grow sinificantly.
(a) Abnormal grain growth in steel A, (b) grain coarsening in steel B, and (c) uniform grain boundary in steel C.

Journal Title and Volume Number (to be inserted by the publisher) 5 In the 1D case, Hunderi and Ryum demonstrated that it is sufficient to describe the effect of the environment on the growth rate of one particular grain size class by a function which depends on the mean neighbor grain size only.
φ(r) r 6 Title of Publication (to be inserted by the publisher) 5 The Side Number Distribution Mullins argued that the ratio 〈s〉 / r must be bounded for large r [8].
Surprisingly, this ratio is unity when the number of sides is 12.
Thus, a closed grain boundary that is shaped like a polygon with the sides formed by arcs of circles intersecting at 120 degrees shows the highest similarity to a circle when the number of sides is 12.
If sufficient time is allowed, side number distributions generated from simulation data always display a finite cutoff at 12 sides (see [14]).

Greater the number of nuclei more will be the clusters and smaller will be the grain size.
Table 2: Number of surface atoms in FCC nanoparticles.
The 2D polycrystal model assumed that all the grain boundaries met at triple junctions, and the topological changes during transformation can be described by Euler’s equations [69]: 3∆V=2∆E=6∆F (11) Where,∆V, ∆E, and ∆F are the change in the number of vertices, number of edges and number of faces or grains respectively as a result of the transformation.
Numbers stands for Monto Carlo number assign to particular grain.
Initialization of Monte Carlo Number Increment (Monte Carlo Number + 1) Make flip if p < e-∆EkT Calculate ΔE Monte Carlo Numbers Determination of Neighbors Selection of Random Site Random Pickup of one site from neighbors to flip Random Numbers Generation, p, between 0 and 1 Search for all visited sites?

For a material to have better magnetic properties after completion of secondary recrystallization, it should have a primary recrystallized texture in which there are not only large number of ideal Goss grains, but also lower frequency of low angle grain boundary around those Goss grains.
According to CSL theory, growing Goss grains meet large numbers of CSL grain boundaries.
Grain boundary character of Goss grains in the primary recrystallized specimens Material Grain Boundary Character of Goss Grains Magnetic Flux Density (B10) Low-Angle G.B.
For a material to have better magnetic properties after completion of secondary recrystallization, it should have a primary recrystallized texture in which there are not only large number of ideal Goss grains, but also lower frequency of low-angle grain boundary around those Goss grains.
For a material to have better magnetic properties after completion of secondary recrystallization, it should have a primary recrystallized texture in which there are not only large number of ideal Goss grains, but also lower frequency of low angle grain boundary around those Goss grains.

Abstract The role of microstructure in susceptibility to hydrogen uptake and property degradation is being evaluated using a number of high strength pipeline steels.
In the present work it is assumed that a large numbers of hydrogen atoms can be trapped at grain boundaries in very fine grained microstructures and numerous hydrogen atoms cannot find appropriate paths (grain boundaries) to diffuse into the microstructure in very coarse microstructures.
To generate different microstructures by the CA model with different grain size, a given number of cells equal to the total number of grains were selected with the random coordination in the blank grid.
Total number of grains=1547 Total number of grains=332 Total number of grains=48 Average Grain Size=5.7±0.05µm Average Grain Size=12.2±0.05µm Average Grain Size=25.1±0.05µm (a) (b) (c) Figure 3: The initial microstructures with different grain sizes generated and used in the CA model.
Grain Size 1 = 5.7, Grain Size 2 = 12.2 and Grain Size 3= 25 µm.

Time is counted as Monte Carlo Steps (MCS) equivalent to a number of reorientation attempts equal to the number of sites dividing the microstructure.
Fig.3 shows the temporal evolution of the number of particles in a pinning configuration for two annealing temperatures T1 and T3. 0 1000 2000 3000 4000 5000 0.000 0.004 0.008 0.012 0.016 0.020 0.024 0.028 0.032 0.036 Critical angle 60° Particle area fraction 1% Température(K): T1 T3 Particle number per grain boundary unit length (-) Time (MCS) Fig. 3.
Particles number evolution per grain boundaries unit length in microstructures containing 1% of particles for two annealing temperatures.
We see at T1, which is the lowest temperature, a stabilization of particles number after 2000 MCS, because the pinning pressure equilibrated the growth driving force.
At T3, this number starts decreasing at the same stabilization time of the T1 case, showing that particles do not retain high angle grain boundaries.

The structural changes observed by SEM/EBSD analysis can be characterized by the evolution of many mutually crossing kink bands at low strains, continuous increase in their number and misorientation angle in moderate strain and finally full formation of a fine-grained structure in high strain.
CA shows compression axis.� &$� Fig. 3 OIM maps of AZ31 alloy with (a) D0 = 22 µm and (b) 90 µm deformed to ε = 0.15 at 573 K and at 3 x 10 -3 s-1. � &$� εεεε = 0.15� εεεε = 0.8�Further deformation to moderate strains leaded to increase in the misorientaion angle and the number of kink band, i.e. further formation of kink band in many grain interiors.
Kink band, followed by new grain formation in the fine-grained sample, is scarcely developed in the twinned grain interiors for the coarse-grained one.
(2) In fine-grained sample, kink bands are first evolved at grain boundaries and then in grain interiors at relatively low strains.
The misorientation and the number of boundaries of kink band rapidly increase with deformation, finally followed by the evolution in-situ of new grains with high angle boundaries in high strain