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IN THIS WAY A SIGNIFICANT REFINEMENT OF GRAIN IS ACHIEVED BY SEVERE PLASTIC DEFORMATION.
Grain size reached the value G4 according to the ASTM.
Grain size reached the value from G5 to G6 according to the ASTM.
As it can be seen from Fig.7a (200°C/15 min) in this case no grain refinement took place, while grain refinement shown in Fig.7b (400°C/15 min) is bigger, than in the samples without heat treatment.
Grain size reached the value G8 according to the ASTM.

Grain Boundary Engineering for Intergranular Corrosion Resistant Austenitic Stainless Steel H.
Recent studies on grain boundary structure have revealed that the sensitization depends strongly on grain boundary character and atomic structure, and that low energy grain boundaries such as CSL boundaries have strong resistance to intergranular corrosion [1-3].
The concept of ‘grain boundary design and control’ [4] has been developed as GBE [5].
In this study, grain boundaries with ��29 were regarded as low-� CSL boundaries, and Brandon’s criterion [8] was adopted for the critical deviation in the grain boundary characterization [3,9].
A number of twins formed in the growing grains compensate grain-coarsening.

The grain size is strongly related to the number of nuclei.
Different pulse number of laser.
From the last section, on the average grain size, the effect of coverage rate is similar to that of its corresponding pulse number.
Table.3 shows the average grain sizes of different pulse numbers and laser intensities.
This could increase the nucleus number, which leads to the smaller grain size.

Results and Discussion Table 1 gives the initial dislocation density inside sub-grain and the mean diameter of sub-grain of the single crystal specimen annealed for various times (S1-S5).
The relationship between the cyclic hour of annealing and the dislocation density is not always linear in five specimens, because the number of grown-in dislocations for each specimen is different by the effect of mechanical polishing before annealing.
Annealing Specimen number First [h] Cyclic [h] Dislocation density [cm-2] Diameter of sub-grain [µm] S1 40 200 1.86×105 75 S2 40 50 2.01×105 65 S3 40 25 2.31×105 50 S4 40 200 9.31×104 105 S5 40 120 4.20×104 165 Table 2 Nominal stress, critical resolved shear stress (CRSS) and shear stress of the main slip system for each specimen.
Nominal stress Shear stress Specimen number σ0.1 [MPa] σ0.5 [MPa] σ1.0 [MPa] CRSS τ0 [MPa] τ0.5 [MPa] τ2.0 [MPa] Diameter of sub-grain d [µm] d -1/2 [µm-1/2] S3 3.1 3.9 5.1 1.16 1.35 1.76 50 0.141 S2 2.5 3.4 4.2 1.02 1.20 1.48 65 0.124 S1 1.7 3.0 4.4 0.83 0.89 1.40 75 0.115 S4 1.7 3.0 5.2 0.70 0.85 1.54 105 0.098 S5 1.3 2.3 3.3 0.54 0.66 1.11 165 0.078 Mecking and Bulian [7] have reported that the values of τ0 ranged from 0.80 to 0.39�MPa for mean sub-grain sizes from 120 to 370�µm in 19 single crystals of different orientations of 5 N high purity copper.
It was seen that dislocations piled�up against sub-grain boundaries.

The aim of adding yttrium was to control b grain growth above the b transus by grain boundary pinning.
In the present case, strengthening of the b texture, occurring during b grain coarsening resulted in strengthening of particular b texture components, which increases the likelihood of a texture modification by selective growth of a variants on the common (110) b grain boundaries into unoccupied large b grains. 1.
While EBSD provides the ability to combine macroscopic texture information with information on the microstructural scale, the requirement of very large EBSD maps to capture a sufficient number of b grains in combination with a small step size in order to capture microstructure information, makes this methodology very time consuming.
It seems that the extensive b grain growth observed in conventional Ti-6Al-4V has resulted in preferential growth of favourably oriented b grains belonging to potentially the original cast texture.
As discussed in [1], large b grains allow relatively free growth of a variants from b grain boundaries with two adjacent b grains having a common (110) normal.

Observations on the as-extruded sample revealed the microstructure prior to HPT consisted of equiaxed grain with a grain size of ~20μm and Mg12Nd intermetallics along grain boundaries: this was determined by TEM in earlier work[9] as shown in Fig. 1.
Figure 2(d) shows the peripheral region of the same disk, where the microstructures of the α-Mg matrix are significantly refined after HPT processing through 1/4 turn although a small number of original grain boundaries are detected, as indicated by arrowheads.
With increase of numbers of revolutions, the initial grain boundaries and twins tend to be gradually lost as shown in Figs 2(b) and 2(c) for the microstructures taken from the central region of the disks after HPT for 1 turn and 5 turns, respectively.
Although the grain boundaries are generally ill-defined in Fig. 4(b), a limited number of small equiaxed grains with average grain size of ~200 nm are clearly visible using a higher magnification, as shown in Fig. 4(c) and (d) via bright-field and dark-field images, respectively.
The inhibition of deformation twinning is expected from easier accommodation of shear strain on many available grain boundaries and easier release of stress concentrations via non-basal slip, cross slip or grain boundary sliding with finer grain sizes.

WQ at 785°C WQ at 830°C WQ at 765°C WQ at 960°C WQ at 890°C WQ at 926°C WQ at 977°C WQ at 1000°C WQ at 1040°C Journal Title and Volume Number (to be inserted by the publisher) 3 occurred among the grains that had already recrystallized, cf.
This is confirmed by quantitative grain size data, which are represented in Table I.
The data suggest that this grain refining has saturated beyond heating rates of 1000°C/s.
This mechanism will have a refining effect on the grain size.
In the end, the final grain size will be the result of a compromise Journal Title and Volume Number (to be inserted by the publisher) 5 between these two opposing tendencies.

A good correlation between the number of adjacent grains (AGA), and therefore the grain shape (granoblastic and xenoblastic), and the durability, was confirmed in a 2006 study [5].
Three of them are characterised by a polygonal grain shape: GI, PS, SG, PS and SG, at difference of GI have a higher grain size and a seriate structure.
AGA Method The Adjacent Grain Analysis (AGA) was carried out in accordance with the EN 16306 Annex C (2013) by means of the free software ImageJ in order to calculate the number of adjacent grains (AG) around median-sized grains.
Afterwards, at least 50 median sized grains were chosen and a manual count of the number of their adjacent grains was carried out.
These differences may be related to the marble grain size.

The transverse (sub)grain size and the number fraction of high-angle (sub)grain boundaries within the austenite phase were about 0.4 µm and 17%, respectively.
All the clearly defined (sub)grain boundaries were taken into account to determine the (sub)grain sizes and the (sub)boundary misorientations.
The transverse sizes of phases and (sub)grains decrease with increasing the strain.
The numbers indicate the (sub)boundary misorientations in degrees.
Misorientation, θ (deg) 0 10 20 30 40 50 60 0.0 0.1 0.2 0.3 0 10 20 30 40 50 60 ε = 4.4 ε = 2.0 ε = 0 0.0 0.1 0.2 0.3 Number Fraction, Ni / N 0.0 0.5 1.0 ε = 0 ε = 2.0 ε = 4.4 Austenite Ferrite Fig. 4.

This paper presents a simple and novel model for low-frequency noise generation in polycrystalline-Si resistors within the number fluctuation model.
Recently, assuming a thin amorphous layer at the grain boundary [5], a number fluctuation model [1] was proposed that considers thermal activation [6], tunneling [7] across the thin amorphous layer {Fig. 1(b)}, and a combination of these two mechanisms.
uniform barrier height and grain size.
Quadratic current dependence has always been observed in poly-Si resistors, which can be explained by the number fluctuation model.
However, three number fluctuation mechanisms have quite different temperature dependences.