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The occurrence of DRX is revealed by optical micrographs that display bulging grain boundaries and the formation of newly formed grains.
As DRX leads to grain refinement and grain refinement leads to an increased strength, DRX is an appropriate instrument to improve the strength of this alloy.
At low strains twins are formed (1) and grain boundaries start bulging (2) but no new grains are formed yet.
Examples of such grains, are indicated with a question mark, cf.
It should be mentioned, however, that by not removing the doubtful grains we probably overestimate the number of orientations of which the crystal c-axis is parallel to the compression axis.

The grain body was characterized by a sufficiently large number of twins of annealing and precipitates of Cu2O oxide in the form of dark gray inclusions of various sizes (from 0.3 to 5 μm) and shapes (mostly round and elongated) having a regular orientation along the rod axis and a stringer-type arrangement (Fig. 1 a).
Almost equiaxed grains are observed in the microstructure of the transverse section of the wire.
The following assumptions were made: the samples were considered as pure copper with a certain grain size.
EBSD Analysis of the Submicron Width Fibber Shaped Grain Copper Fabricated by Drawing, Mater.
Determination of grain size.

The grain to which the cell belongs.
The setting of this property for each cell of the system identifies unambiguously the grain–boundary cells, which have neighbours that belong to a different grain. 2.
The growth length, , for each grain boundary cell, i.
The number of nuclei formed, , is given by , (4) where V is the volume of non–recrystallised ferrite for ferrite recrystallisation and the volume of pearlite regions for austenite formation.
Acknowledgement This research was carried out under the project number MC5.06257 in the framework of the Research Program of the Materials innovation institute M2i (www.m2i.nl).

Pearlite nucleates in the austenitic grain boundary, bainite nucleates preferentially in the grain boundary and sometimes in the grain interior and martensite nucleates preferentially in the interface and generally in the grain interior.
Furthermore, the grain boundaries are the favorable channel of the diffusion, so the grain boundaries become the preferential nucleation sites.
It is obvious that the lath martensite can nucleate and grow not only in the crystal grain interiors but also along the crystal grain boundaries and crystal edges.
A large number of observations indicated that martensite can nucleate in the austenite crystal grain boundaries, the austenite crystal grain interiors, the twin crystal interfaces or the phase interfaces.
The experiments show that pearlite nucleates in the austenitic grain boundary, bainite nucleates preferentially in the grain boundary and sometimes in the grain interior, and martensite nucleates preferentially in the interface and generally in the grain interior.

As a large number of surface monoclinic phase was generated, due to there are a lot of microscopic defects in the phase transition layer, crystals loose, strength of grain boundary lower than that of not aging area and phase transformation layers fracture in the intergranular mode, that damages the flexural strength.
It can be seen that grains in phase transformation region are clear and strong three-dimensional sense, while grains in no phase transformation region is fuzzy.
At the same time, there are a large number of micro-cracks and other defects in the t-m phase transformation layer in surface, which makes flexural strength decrease.
Because there are a large number of defects in phase transformation layer, the flexural strength is lower than that of no phase transformation part.
As a large number of surface monoclinic phase was generated, due to there are a lot of microscopic defects in the phase transition layer, crystals loose, strength of grain boundary lower than that of not aging area and phase transformation layers fracture in the intergranular mode, that damages the flexural strength.

While the mean grain size reduces to ultrafine-grain regime (257 nm), dislocation motion is still involved to carry the plastic deformation.
Secondly, due to large strain gradients in the inhomogeneous microstructure during tensile deformation, a large number of geometrically necessary dislocation that are forced to be present to accommodate the large strain gradient will induce an additional strain hardening.
In this grain size regime, the NS Ni exhibits narrow grain size distribution (Fig. 2 (e) and (f)) with most of grains locating in "small nano" regime (less than 30 nm) where the normal dislocation activity is already suppressed.
As the mean grain size reduce down into the nano-scale regime, the dislocation accumulation is hard to take place in grain interior.
Dislocations are emitted from GBs and glide through the grain then are absorbed at the opposite side of the grain.

The ablation depth is governed by the optical penetration depth, which is the inverse number of the absorption coefficient of the material at the laser wavelength.
The numbers of pulses irradiated were 8, 33, or 250 pulses depending on the irradiated energy.
The Ablation depth is obtained by dividing the numbers of pulses irradiated into the crater depth.
The BMG has no grain boundaries.
Hot electrons pass grain boundaries some times.

Journal Title and Volume Number (to be inserted by the publisher) 3 Steel C Si Mn P S Cr Al N Nb Ti DIN EN 10084 0,14 - 0,19 ≤ 0,40 1,00 - 1,30 ≤0,035 ≤0,035 0,80 - 1,10 - - - - 16MnCr5+Nb 0,19 0,23 0,74 0,011 0,012 1,19 0,041 0,026 0,045 0,001 Table 1 Chemical composition of the investigated steel, mass content in %.
This gives improved grain size stability at higher temperatures that has been confirmed by grain growth investigations.
The grain size distribution is given by means of the cumulative frequency of grains belonging to different ASTM classes; the approximate average grain size is represented by the 50% cumulative frequency.
Figure 4 Calculated nitride and carbide precipitates. 700 600 500 400 300 200 100 0 700 600 500 400 300 200 100 0 NbC NbN TiN AlN 1000 1200 1100 Temperature, °C Mass fraction of precipitates, ppm Journal Title and Volume Number (to be inserted by the publisher) 5 ening temperature (GCT) is associated to the following limit in this investigation: all grains must be of ASTM size 5 or finer; grains of ASTM size classes 4 and 3 are tolerated up to a total volume fraction of 10%; grains of ASTM size class 2 or coarser are not permissible [6/10].
The grain size stability at elevated temperatures is attributed to a sufficient amount of precipitates which guaranty a grain boundary pinning.

If there are other alloy elements or impurities, it maybe also form a ternary eutectic, its melting point lower than the number of binary eutectic, solidification temperature range should be even greater[10].
Semi-solid material of the microstructure of weld metal From Figure 2 and Figure3 we can see the changing of the aluminum alloy grains through the semi-solid processing and the grains are becoming smaller and more garden the whole grain.
Different grains have different bits to, known as anisotropy.
Thus, in a party up the grain raised on the most vulnerable.
Thus, relatively small grains.

Combining with SEM images (Figs. 1 and 2), it is known that as fZ is below 27%, the ceramics is mainly made up of lath-shaped α-Al2O3 grains and rod-shaped grains.
SEM images show that the crack generally propagates along rod-shaped grains as fZ is below 27% (Fig. 5).
Therefore, as the crack-propagating direction is quite different from both the growth orientation of nano-micron fibers and the axial of the rod-shaped grain, the crack is forced to deflect along the rod-shaped grain due to high elastic modulus of the rod-shaped grain and pinning effect of nano-micron monocrystal fibers around the crack tip, and deflection-induced toughening is properly initiated.
However, the ceramics is comprised of lamina-shaped grains as fZ exceeds 27%, resulting in introducing of a large number of interfaces between the alternating Al2O3/ZrO2 layers into the ceramics, so interface debonding is inclined to take place and deflection-induced toughening is weakened.
As for Al2O3/18%, 21% and 24% ZrO2 composites, the matrix comprised of lath-shaped and rod-shaped α-Al2O3 grains, and within rod-shaped grain the nano-micron fibers are oriented in essentially the same direction.