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In order to get fine grain, it is very important to study the correlation between fabrication process and the grain structures of foil stock.
The number of compounds below 1 μm decreases from S1a to sample S2a and sample S3a.
However, the number of compounds with size more than 2μm increases from S1a to sample S2a and sample S3a, which are listed in Table 2.
Table 2 Number of intermetallic compounds more than 2 μm per square meter in 0.55 mm foil stock Compounds size(μm) S1a S2a S3a 2-3 2101.3 6060.0 31351.4 3-4 253.2 580.0 4324.3 4-5 0.0 220.0 270.3 ＞6 0.0 0.0 270.3 Total 2354.4 6860.0 36216.2 Effect of Homogenization Conditions on the Grain Structures of AA8021 Aluminum Alloy Foil Stocks.
The grain structures of 0.55mm gauge foil stocks are shown in Fig. 5.

A number of UV laser lines can also be employed to provide depth profile.
However, in the monochromatic green colored PL image, a large number of dark lines and bright dots are observed.
These all probably correspond to low angle grain boundaries.
One can notice that in the SWBXT image, there are a large number of low angle grain boundaries running from the off-center facet to the edge of the wafer.
Colin Wood) and by Dow Corning Corporation under contract numbers N0001405C0324 and DAAD1701C0081.

Before rolling, the material was annealed at 753 K for 8 hr. to produce a large grain size of 30~60 µm.
In both microstructures, it is evident that the original grains with the size of 30~60µm have been greatly refined.
Their grains are 2.2 and 1.4µm, respectively.
Number next to symbols indicates the pressing number by ECAP.
Significant grain refinement took place during both processes owing to introduction of large shear deformation.

The effect of interstitial and substitutional impurities on grain boundary (GB) cohesion in the series of B2-TiMe alloys is studied from first principles using pseudopotential approach.
The TiMe(310) surface was simulated by a slab model with 10 atomic layers of Ti and Me and the same number of layers for vacuum gap between slabs.
The number of sites for H atoms at the surface where they can be trapped is larger than at the grain boundary because they are limited to the space between matrix atoms.
Boron in TiMe alloys prefers to segregate towards the grain boundary rather than the surface.
The grain boundary expansion and hence the IS contribution is small for H and B but it is larger for C.

A Study of Carbon Nanotubes as Cutting Grains for Nano Machining J.
In this project, CNTs were directly used as cutting grains.
In this project, CNTs were directly used as cutting grains.
We fabricated a number of CNT wheels (Fig. 1(a)) for the experiments (Table 4).
CNTs can be used as cutting grains.

The Effect of Annealing on Mechanical Properties, the Number of Fluidity, and the Size of Coherent Scattering Regions in AMg1, AMg5, and AMg6 Alloys N.
It is shown that the fine-grained alloy recrystallizes faster than an alloy with a large grain size.
In [2], the increase in the recrystallization rate of a fine-grained alloy is attributed to the fact that the initial grain boundaries favored nucleation sites.
The shear lines and transition lines were more easily formed in a coarse-grained alloy than in a fine-grained alloy.
In the paper [16], it is assumed that the high strength of an alloy in a state after equal-channel angular extrusion is associated with an increase in grain size, dislocation density, and the number of dispersive phases.

With the time going, testing results show that coarse-grained alloys with larger grain size have higher impedance values and smaller corrosion current densities, indicating a better corrosion resistance than fine-grained specimens.
As temperature rises, grain size increases accordingly.
Grain growth is a thermally activated process, and the grain boundary area is the main source of energy, thus the system will evolve to reduce grain boundary quality and followed by the increase of grain size[13, 14]. 1# specimen shows fine grain with apparent and abundant short rod-like and sheet-like δ phases pinning at the grain boundary (Fig. 1a).
As shown in Fig. 2b, 1# and 2# samples have thinner grain size but more positive OCP values, by contrast, 3# and 4# are coarse grained but less positive OCP values.
For 1# and 2# specimens, although they also have numerous grain boundaries, but it can be clearly seen that these boundaries are occupied by a large number of precipitated particles - the δ phase, which may block the diffusion and slow down the formation of passive films.

One can build up a very significant amount of plastic strain in the material by increasing the number of passes.
The development of ultra-fine-grained materials with fewer number passes would make ECAE commercially attractive.
It is suggested that, in this type of material it might be possible to get ultra-fine/nano-crystalline material during ECAE with relatively less number of passes.
Some grains less than 100 nm are indicated by arrows.
It is suggested that in material with non-shearable particles it might be possible to get ultra-fine/nano-crystalline material during ECAE with relatively less number of passes.

A number of physically based models are combined in order to predict microstructure development during hot deformation.
The models are applied to a number of laboratory experiments made on 304 austenitic stainless steel and the model parameters are adjusted from those used for low alloyed steel mainly in order to obtain the right kinetics for the influence of solute drag on climb of dislocations and on grain growth.
Fig. 5 shows the results for the grain size.
As the temperatures before quenching also increases with increasing number of roll pairs the time for recrystallization and grain growth will increase as indicated by the ovals in Fig. 4 and Fig. 5.
Calculated grain sizes for the different tests.

Near the sheet surface, large grain growth to mm lengths was observed at 60 to 160°C, whereas at the 1/3 thickness level grain growth of CReX grains starting at about 1 µm took place at 240 to 275°C.
From the measured grain boundary velocities, a grand scheme encompassing the lattice and grain boundary diffusivities of Fe in Al with the grain-growth activation energies was formulated.
Grain growth at 60-160°C.
Composite grain growth kinetics.
If the thermal energy becomes so low that Fe solutes are immobile and few in number, the drag force approaches zero and interface migration can proceed at a much faster rate as depicted.