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Contributed to the refining effect of Zr element, the average grain size is about 30μm.
The fine lamellar LPSO structures either distributed at the grain boundaries or extended from grain boundaries into inner grains.
The average recrystallization grain size was about 4μm.
The strengthening effect of fine grains is obvious.
In other words, the former directly contributed to the strengthening and the latter promote the improvement of ductility with the increment of the number of the slip systems.

In addition, the thermal diffusivity of the grain with average value was analyzed.
In the months of harvest, there are many grains to be stored.
Moreover, it will be considered the coefficient of thermal diffusivity of the average grain.
The finite difference method consists of the discretization of the problem domain in a finite number of elements and approximations of partial derivatives by finite difference quotients.
Sun, Rice Grain Size and Quality.

Grain family 2, less in number, has <10 1 0> along the rod axis with the other crystal axes defined by a 360˚ rotation about the <10 1 0> axis.
As a result of cooling, <0002> grains are under tension and <10 1 0> grains are under compression perpendicular to the rod axis.
Along the rod axis grain families 1 and 2 have the same coefficient of expansion and are constrained by grains less in number and with similar coefficients of expansion so the thermal strains in grain families 1 and 2 are nearly zero.
Nevertheless, the thermal strains in other grain orientations along the rod axis, such as grains with <10 1 1> along the rod axis, are tensile although the population of these grains is much lower than grain families 1 or 2.
The Schmidt factors for twinning for grain family 1 and grain family 2 are 0.37 and 0.49 respectively so, to a rough approximation, grain family 2 twins first and grain family 1 only begins to twin when all the appropriate orientations of grain 2 have twinned.

The micrographs were used to determine the grain refinement and average grain size values.
Strength and ductility profiles with increasing CGP pass number for; (a) AISI 304 samples, (b) pure zinc samples The stress-strain graphs of both materials are demonstrated in Fig. 5.
In addition, Fig. 6 represents the variation in strength and ductility levels for both materials according to the imposed pass number.
Observation of strength declines following a number of passes points to the competition between severe deformation induced hardening and micro-cracking plus flow softening mechanisms related to annihilation of dislocations via dynamic recovery mechanisms [18-20].
Park, Constrained groove pressing and its application to grain refinement of aluminum, Mater.

The number of the activated slip planes depends on the relative position between grain orientation and tool edge.
The single grains can be distinguished clearly due to the different spring back of the grains and the separation along the grain boundaries.
The more the number of the activated slip planes are the more dispose the material for hardening is.
The number of the simultaneously active slip systems is high in the directions with low Miller-indices.
The number of the used tetrahedral elements is 72500.

With the increment of annealing temperature, the peak intensity ratio of Ti3Al(201) and Ti (002) gradually increases, whereas, the number and intensity of XRD diffraction peaks lessens after the annealing at 650 ˚C-850 ˚C, and this indicates that the interface melting & mixture and grain coarsening has occurred at this time; with the increment of temperature at 650 ˚C-850 ˚C, the solid solubility of Ti and Ti3Al has increased, correspondingly, the lattice constant has increased, this is shown as the diffraction peak of Ti3Al(201) and Ti (002) diffraction peak has shifted to the left.
The grain boundary can be clearly seen and grain significantly grows, indicating that Al and Ti have diffused completely and finally formed α-Ti solid solution, this is also shown by XRD.
Grain growth will lead to the roughening and even disappearance of the interface.
In Fig.3b, the groove angle formed by two grains in A layer and a grain in B layer is significantly greater than the angle by a grain in A layer and two grains in B layer, so the pinch-off phenomenon doesn’t occur in the A-layer; whereas, B layer will be pinched off by A layer grain along the direction of groove-angle expansion, and this eventually leads to the coarsening of the microstructure.
On the theory of normal and abnormal grain growth.

Abrasive grains size was F400/17.
Abrasive processes (including lapping) have a large number of parameters that can be varied in order to obtain the desired process output.
Abrasive grains size F400/17 was used.
Obtained Ra values are rather high as for lapping what can be caused by abrasive powder number.
Powders with number F400/17 are generally utilised for rough lapping.

The bands must encompass many initial grains.
The analysis in Fig. 3b-d) and Fig. 4 indicate instead that groups of grains form by grain-grain interactions and rotate together toward one or the other variant of the β fiber during deformation.
Such an average is based on the total number of bands and most of the volume of material in the image of Fig. 3b) appears to be in the thickest bands.
Mechanisms of grain-grain interaction during deformation processing remain to be identified.
In turn, the texture variants reflect grain subdivision and the processes of grain subdivision include deformation banding.

In both cases microbands were found in the majority of grains examined with many having more than one set.
The material was recrystallised containing equiaxed grains with an average grain size of 80 ± 12 μm.
Results Microbands were observed in 41 grains after forward/forward (F/F) torsion and 60 grains after forward/reverse (F/R) torsion.
The analysed grains mostly displayed either one or two sets of microbands with a few grains exhibiting three sets of microbands; the exact numbers are summarised in Table 1.
Number of grains analysed and the number of sets of microbands within each grain Total grains analysed No. grains with 0 MB's No. grains with 1 MB's No. grains with 2 MB's No. grains with 3 MB's 0.25 F/0.25F 41 6 13 26 2 0.25 F/0.25R 60 10 30 24 6 An example grain of the forward/forward material is shown in Fig. 2a.

Powder mixture Pressure [GPa] Number of rotations Cu25Cr 2, 4, 6, 8 0.25, 1, 2, 5 W20Cu (6), 8 (1, 5), 0.25, 1, 2, 5 After HPT the disc-shaped samples were tested for their density, hardness and grain size.
These measurements were taken in gradual steps along the diameter at positions 0.5 mm apart, with a total number of 15.
a b Grain size analysis via SEM and XPA.
From the SEM data, grain sizes in the range of 50-500 nm were evaluated resulting from finer subgrains as being evident from the continuously changing contrast within the grains (Fig. 4).
Parameter description: m- median grain size, σ- variance, L0- volume weighted and d- area weighted grain size [7], r = radius.