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It can be seen that the grains are approximately equaxied.
The mean grain size, measured by the line intercept method, is about 50 μm.
After four passes, the grains were further refined as shown in Fig.1(c).
After eight passes, the grains became so refined that obvious ultra-fined grains would be seen by optical microscope.
The variations of yield and ultimate strength vs number of ECAP are clearly shown in Fig.5 With the increase of the strength of the ECAPed specimens, its elongation decreased obviously from 90 % of as-received sample to 8.9% of 8-pass sample.

The grains show a much larger content of Na than they do for Ca.
Fig. 5: Electron probe mapping tracing Na over Fig. 6: Electron probe mapping tracing Ca over the cross section of an AlF3 "active" filter grain the cross section of an AlF3 "active" filter grain Discussion A model is proposed that assumes that Ca in either atomic or ionic form diffuses into the AlF3 filter grains.
Figure 5 shows that Na is evenly distributed throughout the filter grains.
However, for Ca Figure 6 indicates that Ca has only entered the surface area of the grains.
British Patent Number 1,148,344 [12] M.

For example: Event Grain Growth can have two rules: nucleation and growth.
Beyond this, locations of grain nuclei are also generated randomly along austenite grain boundaries.
After the CA cell becomes a nucleus of a new recrystallized grain, the grain growth process is simulated.
Finally, the cell coverage by the recrystallization front or another grain is calculated by: , (11) where: – the level of coverage of the i–th cell in the previous (t-1) time step, rx – number of recrystallized neighbours (stored energy driving force) or number of neighbouring cells that belong to recrystallized grains (grain boundary curvature driving force), vj – velocity of the recrystallization front or recrystallized grain boundary, tstep – length of time step, – cellular automata cell size.
GrainId (grain number), GrainState (e.g. recrystallized, unrecrystalziaed), PhaseType (e.g. ferrite, austenite, boundary), StoredEnergy (the stored energy of deformation) or CarbonContent (carbon concentration in the material).

The reason is the limitation of the number of active deformation mechanisms, especially when compared with cubic metals.
Even at high temperatures, this leads to complex rolling plans with a high number of rolling passes at comparably low degree of deformation per pass.
The reduction in the number of processing steps to final gauge, Fig. 2, leads to shorter production times and a decrease in production costs.
The refinement in grain size was attributed to the dynamic recrystallization and grain growth which was influenced by the presence of the particles causing possibly particle assisted recrystallization and retardation of grain growth [15].
The AZX310 sheet contained a fine and uniform grain size distribution with ab average grain size of 9.1 µm and a high number density of fine Ca-rich particles distributed uniformly through the sheet thickness.

However, most of the grains were in FCC phase, while the BCC phase with a lath shape only distributed between the FCC phases.
The Al1.3FeCoNiCuCr HEA coatings without adding Mn have 7 diffraction peaks, which are numbered left to right respectively from 1 to 7 in figure 1.
According to Gibbs rule, an alloy consists of n elements can only have equilibrium phases number of n+1, while the non-equilibrium solidification process will lead to the phase number p>n+1.The high entropy effect causes the Al1.3FeCoNiCuCr HEA coatings more likely to form the simple phase of FCC and BCC structure and less likely to form those brittle intermetallic compounds which have a phase number that is less than 7[10].
The sub-boundary can be observed clearly in the region, and some of the grains in this region can be observed.
The indexing result shows that it a typical FCC structure, indicating the grain possesses a simple FCC phase structure.

Hydrothermally produced BT nanopowders show a number of structural characteristics not seen in powders prepared by conventional solid-state reaction at high temperature.
Morphology and grain size were investigated by SEM and TEM.
HRTEM images (a) a typical lattice image of nanocrystalline BT grain of size of 75 nm in sample A, (b) a surface profile HRTEM image of part of a BT grain with size of 80 nm in sample B.
This may be caused by the high strains in the grains.
A uniform diffraction contrast across single grains was observed.

The contour numbers represent percentage efficiency of power dissipation and shaded region shows the instability region.
Observation the microstructure, its average grain size after deformation is 56μm(Fig.4.
(a) shows the morphology of its crystals is equiaxial, the size of grains is coarse and the grain boundaries is straight.
(d) shows the morphology of its crystals is equiaxial, size of grains is fine and the grain boundary is straight.
Processing map for the CL60 wheel steel at a strain of 0.5;the numbers represent percent efficiency of power dissipation and shaded region shows the instability region.

The grain refinement of the primary crystal α makes it changes from coarse columnar dendritic structure to fine equiaxed structure, the mechanical properties of the alloy greatly improved.
When insulating 12h, the grains further coarsening, and some of grain began to deteriorate roundness, and differences between the sizes of the grains become larger, that is, grain uniformity decreases.
When the alloy was heated to 540 ℃, the primary α becomes irregular, large differences in the size and dimensions, the grain coarsened.
And the insoluble phase in the alloy grain boundaries and intragranular dissolve more fully, components are more uniform, the mechanical properties the better.
Conclusions There are the main columnar α phase, eutectic (α dendrites + eutectic silicon) in B refined alloy Al-7 wt% Si, heat treatment makes the dendrite α smaller, the number increases, eutectic particles tends to round, the structure and hardness have been changed.

Recently, a number of solutions were proposed to overcome the corrosion problems, like polymer films [7] and aluminium alloyed coatings [8].
The reduced grain size is a necessary condition for achieving the superplastic behaviour.
It is clear that the grain refinement effects of the process are evident.
In the nugget zone it is impossible to distinguish the grain boundaries while on the unprocessed side the grain boundaries are easily distinguishable.
In the FE model, the complex shape of the FS Processed zone, that is a cone-like zone with small equiaxed grain and a surrounding zone with a bigger grain size, was modelled as an uniform region of processed material.

.% Zn after ball milling with an average grain size in the range of 33-12nm.
Refining grains could create a higher concentration of grain boundaries (GBs) which provide barriers to inter-grain dislocation motion, making the material harder to deform further, as suggested by the well-known Hall-Petch (H-P) relation [8-10].
Modeling results indicate that there is a transition from dislocation generation at sources within grains to grain-boundary mediated dislocation generation in the grain size range between about 100 to 10 nm.
The advantage of SPT over nanoindentation and micro tensile tests is the deformation zone where a large number of grains undergo deformation within the shear zone and overcomes the problem of stain gradient plasticity effects, grain size effects as well as the specimen size effects [13].
Therefore, the controlling deformation process can be mediated by dislocations inside the grain boundary or in a narrow "grain boundary affected zone" [31].