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In these last cases, the presence of such microbands depends on the grain size and so depends on the strain accommodation processes between grains.
Such kind of samples contains only few grains in their thickness.
In fact, rolling deformation is more constraint than tension and, consequently, rolling can require the activation of high number of slip systems, for some grain orientations, independently of the strain accommodation process between grains.
It is mentioned that dislocation structure for such coarse grain multicrystals is, in some cases, not uniform within individual grains.
Also, the microstructure in small regions near the grain boundary can be different from the one in the grain interior.

A large number of publications relating to the influence of dispersed particles on the recrystallization kinetics of two-phase alloys are currently available as cited in references [6], [7] and [8].
Vickers hardness number for HRS foil R2 = 0,8358 0 50 100 150 200 10 20 30 40 50 Vickers Hardness Number Tensile strength MPa2.7 Recrystallization of the foils.
The precipitation of fine particles inhibits the formation of recrystallization nuclei thus retarding recrystallization and giving a large recrystallized grain size.
In the first case, irregular coarse grains (ASTM 2) can be observed, whereas foil from HRS presents uniform fine grains (ASTM 6).
Irregular coarse grains of foil CCS (ASTM 2) Fig. 9.

At the same time, The YSZ grain boundary resistance value increased exponentially as the porosity of the coating increases.
As the spray distance increases, the "cauliflower-like" head became larger and larger, and the number of fractals increased.
When the spray distance was 1400 mm, the number of "cauliflower-like" fractals reached six, showing an obvious "umbrella" shape and the surface was uneven.
The high frequency part contained two small capacitive reactance arcs, which were the YSZ crystal grain and the grain boundary impedance response.
Fig. 8 Variation of grain boundary impendance of 7YSZ coating with porosity.

During this period a large number of helium bubbles are formed and aggregate into the grain boundary of the CLAM alloy.
As shown in Fig. 1, the helium bubbles of different sizes will be scattered distribution at the grain boundary. 
Under a vertical tensile stress on the grain boundary surface, a local strain concentration near grain boundary will occur.
The size of grain boundary and the distance between the internal bubbles represent by side BC and AB in Fig. 1.
This stress leads to the strain concentration in the grain boundary of CLAM including a He bubble.

In high deformation zone, dislocation of the grain boundary is extinguished by reversion and recystallization action of the grain, which remove space of niobium and titanium carbontride precipitation and the make ratio deadlock space being vanished.
The austenite grain alteration case in high temperature with 200 times enlarged is shown in Fig.4.
Fig. 4 Austenite grain structure at 940˚C with different time span (Tips: a 0.2s, b 0.8s, c 2s, d5s) It can be read from Fig.4 that the sample presented lath-shaped grain microstructure with 0.2 second span.
Through iterative line-cutting method to get the average number, estimate the austenite grain size to be 17.22µm and 28.87µm at 2 seconds and 5 seconds span.
The growing trend of the austenite grain is due to reversion and part recystallization action in the span time between two passes.

Samples name, uA express micro AlN, nA express nano AlN, C represent CNT and number represent CNT content.
In the process of high temperature sintering, Al-Y-O middle phase is volatile, only a small amount of Al-Y- O middle phase residue in grain boundary formation of grain boundary phase.
There was less intermeditate phase residue, Main distributed at triangle grain boundary of AlN and the grain boundary of AlN-C.
Flake graphite layer has a certain block on the sintering of AlN, inhibits AlN grain growing up.
When adding enough quantity, and full reaction with Al2O3, oxygen removal clean, intermeditate phase very little residue, get full continuous grain, reached the highest thermal conductivity, When much adding relative to the Al2O3 on the surface of the AlN, too much of the grain boundary phase residual, grain boundary impurity content is high, thick grain boundary, easy to diffusion in AlN lattice in the process of sintering, formation grain internal defects, and thermal conductivity is reduced.

This is mainly because of particle CNT has produced certain obstacles to neck formation of the particles and the grew up grain size of the sintering metaphase, not produced apparent effect on residual stomatal eliminate to grain boundaries enrichment in the sintering later.
Because of SPS has the characteristic of rapid heating, sintering belonging to the extreme non-equilibrium process, the sintering temperature increase made AlN grain growth driving force increases ceaselessly, when the driving force is large enough, can overcome CNT barrier on migration of grain boundary, so that AlN grain grew rapidly, even so, CNT on grain growth inhibition is still very obvious.
The grain size decreases and presence of certain defects in composite ceramics compared to the single-phase AlN.
As shown in the figure, thermal conductivity increased accordingly to the increases of sintering numbers under 1550°C sintering temperature, employing sintering process of 1550°C/3min×3, thermal conductivity of A1N/CNT is 145W/m·K, higher than the A1N.
This is mainly due to CNT tubular structures were not destroyed during the low sintering temperature, CNT mainly distributed in the AlN grain boundary and there is less AlN grain defect.

The material grain size is about 1 um or even smaller and the distribution of elements in such materials is even.
The versatility of SPS allows very quick densification to near theoretical density in a number of metallic, ceramic and multi-layer materials in a low vacuum environment (~5Pa) [4].
improved with the decrease of materials crystal size and with the increase of uniformity of rare earth element distribution; (2), the grain boundary energy will increase with the decrease of material crystal size, which helps the rare earth diffuse from materials inside to materials surface.
The EDAX analysis results show that the point 1 is molybdenum crystal, the rare earth elements also appeared because the grain diameter is smaller than that of the electron bundle; however, the rare earth elements, molybdenum and oxygen element separated along the grain boundary (points 2 and 3), the variation of every element content is small.
It can be clearly seen from Fig. 5 that the grain size of materials is far smaller than that of the materials sintered by dry hydrogen furnace, which is also agreement with the results above.

The samples produced by powder metallurgy, with grain size around 10 µm, are ideal for determination of intrinsic parameters.
Using expression (1) [8] the domain wall energy γ , can be found: 7.1 1 L M D s ⋅ = γ (1) where L is the grain size, Ms is the magnetization of saturation, D is the domain width.
Expression (1) has validity only for small grain size.
But this problem is avoided in our study because the limiting grain size is 48.5 µm, well above the grain size of our samples.
It should be added that the values γ, Dc e δ are necessary parameters in models for the estimation of variation of coercive force as function of the grain size, fact that increases the practical relevance of this determination.

The surface morphology also indicated that copper grains of very fine crystallites were incorporated in the metal-organic composite films by the introduction of hydrogen gas to the plasma.
On the other hand, the morphology of film obtained with an H2/Ar mole ratio of 0.24 was composed entirely of very fine crystallites grains, and grain boundaries in the film were clearly observed.
These results are consistent with the XRD results in Figure 1, which means that the Cu grains are formed in metal-organic composite films with the introduction of hydrogen gas to the plasma.
The results indicate that addition of hydrogen gas to the plasma strongly affects the grain size in and the morphology of the film.
Research was supported by New Chemical Process Program under contract number M1-0322-00-0001-04-L14-00-001-001.