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The results show that grain size and the dielectric loss of BZT-BCT-Mn-Nb ceramics increase as raising the sintering temperature.
It is clearly shown that ceramic samples exhibit regular shaped grains with clear grain boundaries.
With increasing sintering temperature, the average grain size increases.
The phenomenological kinetic grain growth equation proposes that the increase in sintering temperature grain size increases[9].At 1380oC, the grain size becomes uniform, lead to a homogeneous and dense microstructure of sample.
However, further increasing of sintering temperature (at 1420oC) makes the microstructure inhomogeneous and the number of pore increase.

Based on such combination, a new method for manufacturing of semi-products with ultra fine grain structure by drawing with torsion was developed.
As it is known, to refine the grain structure of metal, it is necessary to obtain such a stress-strain state, which will provide share deformation.
Carbon steel grain size changing after combined deformation by drawing with bending and torsion.
Under the same technological conditions the medium carbon steel wire Steel 50 grain size decreases by 2.73 % and 13.66 %, respectively.
Nikitenko, The possibility of manufacturing long-length metal products with ultra-fine grain structure by combination of strain effects, Key Engineering Materials. 685 (2015) 487-491

But it is not the grain of ZnO wettability, so it cannot be completely surrounded by ZnO grain[3].
Table 3.1 is different in sintering temperature, ZnO pressure sensitive resistors electrical performance testing structure, further reflecting the sintering temperature rises from the table, the number of grains contain reduced, leading to reduce potential gradient fall.
This suggests that, with the rise of the time of heat, will promote the growth of ZnO grain, make the generation of ZnO ceramic large grain scale microstructure.
This is because when they reach a certain temperature, ion will overcome the potential barrier to produce migration, causing sample shrinkage and densification process, grain, keep touch each other to formSilent stoma and lord of grain boundaries, sample in 1145 ˚C of grain boundaries of porosity although have reduced, but not by, it was the lord of grain boundaries, more and more of the remaining stomatal don't close become silent grain surrounded porosity, it is difficult to eduction.
To 1150 ˚C, the remaining stomatal has all become silent porosity, each grain has close contact between the formation of grain boundaries; Continue to heat up again to 1155 ˚C, grain growth (figure 1), but Bi203 etc under high temperature liquid additive easy to be volatile, surface porosity will be a little increase, resulting in its density slightly reduce[5].

On the other hand, the protective oxide is surmounted by a precipitated layer, made of hydroxides [1,3] and scattered octahedral crystals of NizFe(3-z)O4 [4,5,6], the number of which depends on the media saturation [1,7].
Regime B corresponds to a competition for diffusion between bulk diffusion and grain boundary diffusion whereas regime C considers only diffusion by grain boundaries.
The equation of Hart [15] allows linking the apparent diffusion coefficient to the grain boundary diffusion coefficient (Dgb) and to the bulk diffusion coefficient (Db) following Eq.7: gbb app DfD)f1(D ×+−= (7) with f the volume fraction of short circuit which can be defined by Eq. 8, g 3 f δ = (8) in which g is the grain size.
The major part of this diffusion takes places along oxide grain boundaries.
Moreover, oxygen diffusion coefficients at the grain boundaries has been estimated and compared to values extrapolated from higher temperature.

Euclidean Voronoi Diagram Suppose that a finite number of distinct geometric entities, which we call generators, are given in 3D space.
If we allocate all locations in this space with the closest member among the generators, the partition of the space with a number of regions results.
Since the angles and distances are represented in floating numbers, it is inevitable to employ tolerances when numbers are compared to test.
Also,the distinct number and value of angles for each crystal structure (BCC, FCC, and HCP) are introduced.
The presented method, in the future, can be applied to characterize grains with B2, L11, L12 and other structures as well.

In figure (a), columnar grains packed loosely, without intergranular phase between them.
Fine grains tended to decrease and coarse grains tended to increase.
In figure (b), intergranular phase began to show up, bonding the columnar grains together.
All samples own a typical duplex microstructure composed of fine matrix grains and elongated grains, except for sample YOCl 2, which exhibited porous structure (relative density 82%).
As for YOCl- added samples, we see an obvious decrease of pore numbers as YOCl addition increased.

The number-based mean grain size was obtained from TEM images by two methods: (1) a linear intercept method, where ~50 lines were drawn in perpendicular directions, and (2) the maximum dimensions of 400 individual grains were measured, which also generated distributional histograms.
Although most of the grains were less than 300 nm, there was a large range in grain size and some were over 1 μm.
Material View Point Measurement Method Dimension 1 Dimension 2 Mean Aspect Ratio Axis (nm) Axis (nm) (nm) Forged Disk F Linear intercept N -- N -- 461 ~1 Individual grains* N 462 N 444 453 1.04 N Linear intercept N 448 F 239 343 1.88 Individual grains* N 460 F 246 353 1.87 Rolled Plate F Linear intercept R 490 N 417 454 1.18 Individual grains* R 502 N 421 461 1.19 N Linear intercept R 473 F 230 351 2.06 Individual grains* R 492 F 233 363 2.11 R Linear intercept N 431 F 231 331 1.87 Individual grains* N 412 F 237 325 1.74 * obtained from a total of 400 grains.
A predominantly UFG structure was retained, although a significant population of coarser, micronsized grains imparted a bimodal aspect to the grain structure.
Lavernia, in: Ultrafine Grained Materials IV, edited by Y.T.

It is shown that microdiffraction paintings in alloy AMC in the bulk of grains are observed uniformly distributed particles of the second phase.
However, despite the significant number of experimental works, produced by IPD in aluminum alloys still have not found features of the fine structure of deformed aluminum alloys.
In the bulk of grains are observed uniformly distributed particles of the second phase.
In the bulk of grains are observed uniformly distributed particles of the second phase.
Matlock, Overview of processing, microstructure and mechanical properties of ultrafine grained bcc steels.

It is found that as the coating thickness increases mean grain size increases.
As thickness increases, since smaller grains tend to have surfaces with sharper convexity, they gradually disappear by feeding the larger grains [11].
Thiel: Patent Number: US6413581B1 (2002)
Honjo: Patent Number: EP1081108A1 (2001)
Hurst: Patent Number: EP 254870A2 (2002).

The results showed that tensile properties of the welded specimens were lower than those of base metal due to coarsening of the matrix ferrite grains and loss in the fraction balance of ferrite and austenite phases in the weld metal zone, where fracture took place.
Although HE in DSSs has been studied to some extent [3,4], the major reports are restricted in the base metal; only a limited number of studies have been made on the weld joint of DSSs.
Comparing the low magnification microstructures, M(a), H(a) and L(a), it is found that the ferrite grain size increases with increasing heat input (decreasing velocity); grain size is largest in L(a), medium in M(a), and smallest in H(a).
In specimen H, austenite phase exists as plates covering whole ferrite grain boundaries and as small island-shaped particles inside the ferrite grains.
The microstructure of specimen L is similar to that of specimen H, but austenite does not cover the whole ferrite grain boundaries.