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Each point corresponds to the total number of hillock phases within 100 Am width of a line.
For Pb atom injected into Sn-phase grains, the corresponding volume size factor Ωsf is + 29.05 % [7]; it is equal to zero for Pb atom into Pb-phase grains.
Similarly, for a Sn atom injected into Pb-phase grains, its Ωsf is -8.25% [7].
Again, it is equal to zero for Sn atom injected into Sn-phase grains.
It is easier for Sn atom to move into the Pb-phase grains rather than into Sn-rich grains at low temperatures.

Number of DCAP cycles (N) was varied from 1 to 2.
Number of revolutions was varied from 1 to 15 (strain is e=4.1-6.9).
Increasing of number of revolutions up to 15 (e=6.9) leads to certain coarsening of the structure.
Probably these particles situated on grain boundaries and inside grains deter nanoscaled grain growth and do not restrain active development of dynamic recrystallization.
It is known that shock waves create large number of lineal defects.

Especially, a large number of thin-wall covering parts are produced by the means of the sheet pressing.
It has been discovered that there are a great number of twins existing in grains of magnesium alloy sheets, which are deformed at 200~300ºC and warm-rolled by 15%, though rolling temperature is not too low.
The grain are uniform distribution equiaxed grain, average diameter 14µm (Fig.3a) and with high mechanical properties.
After 120minutes, some grains grow bigger.
If the annealing time period increases, some grains grow bigger.

The C hk.0 and the q1 and q2 parameters have been numerically evaluated and compiled for a large number of hexagonal crystals in [18].
This value can be converted into different average size values averaged over the number (arithmetic) area or volume of coherently scattering objects, especially, if assumptions are made about the shape and size-distributions of these objects [24].
The TEM grain size, in most cases, is rather the average size of regions delineated by large-angle grain boundaries.
This means that with increasing size, in general, the grain size becomes larger then the subgrain size since here the grains can accommodate more then one subgrain.
This result is interpreted by assuming that the vacancy accumulation in the grain boundary region is larger than in the grain interior or matrix regions.

The addition of trace amounts of nano-HA decreases the grain size of the matrix refined and increases the number of grain boundaries, hindering the motion of dislocations and leading to an improved tensile strength of the composites.
First, fine grain structure increases the number of slips during plastic deformation so that the deformation is evenly dispersed in many more grains.
Secondly, a number of twists of the grain boundary surface increases with decreasing grain size, making the spreading of micro cracks less favorable.
Furthermore, since at high temperatures, the number of slip planes of Mg matrix increases from one to three and impurity atoms are gradually dissolved in the matrix [17], the number of grain boundary impurities and grain boundary viscosity sliding resistance decrease.
Additionally, higher HA content leads to reduction of the grain size and an increase in the number of grain boundaries.

At the same time, it permits a reduction in the number of ECAP passes required, which produces a more homogeneous ultrafine-grained (UFG) state, and, finally, in a decrease in the structural anisotropy and enhanced properties.
Microstructure of the asreceived Grade 2 CP-Ti rods has equiaxed grains in both cross and longitudinal section with α-phase grain size of about 75-80 µm (Fig. 1).
Some dark coarse particles, observed at grain boundaries and inside grains, are oxide phases [12].
Effect of the number of ECAP passes on mechanical properties of Grade 2 Ti billets.
The grain/subgrain size is reduced to 150-250 nm.

The banded structure and grain size were evaluated according to ASTM E1268-01 and GB/T 6394-2002.
For sample 1, the banded structure was almost eliminated after the heat treatment process and the band structure grade decreased to grade 2.5; also, the grain size became finer and the grain size grade increased to grade 8.8.
The sample 2 had a banded structure grade of 3 and grain size grade of 8.0.
In addition, banded structure was more prone to crack, especially in the coarse grain zone.
For that of sample 2, size was small but huge in number, it also existed some long strip type sulfide inclusions.

The grain boundary can still be seen in the transition zone, and a lot of twin grain in different planes mutual settlement in the original large grains.
Original coarse grains of the matrix which are away from the surface is clearly visible, and little single-line twins are distributed among the original coarse grains.
Overall, the number of twins gradually decreased along the depth direction, but there is some heterogeneity, the corresponding grain size increases gradually along the depth direction, a continuous variational gradient is presented.
There are a small number of twins far from the surface layer (more than 250μm).
The grains strengthening may be caused by a small number of dislocation(Figure 1b).

The sample preparation spin coating number is 6, the average grain size is in nanometer level, and the thermal treatment temperature is 450, 500, 550, 600℃, respectively.
The D values of the average size of corresponding grains are shown in table 2.
Table 2 Average grain size of doped ZnO thin films of Al and Co sample number Diffraction peaks FWHM D[nm] Al001 100 0.478 17.7 002 0.451 18.9 101 0.485 17.6 Al002 100 0.321 27.1 002 0.353 24.6 101 0.389 22.2 Al003 100 0.336 25.7 002 0.313 28.0 101 0.395 21.9 Al004 100 0.272 32.7 002 0.297 29.7 101 0.352 24.7 Obviously, as the sintering temperature rises, the fwhm of the diffraction peak gradually decreases and the average grain sizes grow, indicating that the higher the temperature is , the better the crystallinity of Zn0.98-xCo0.02AlxO films is and the less defects the films have.
Samples with smaller grain sizes will increase the scattering of light on the surface of the films and reduce transmissivity.
But relative to other samples, Sample Al004 will move toward the direction with higher energy, which is due to large grain size of the films of sample Al004, few defects of grain boundary, small resistivity and higher carrier concentration.

Microstructure of Ti was found to be refined to a grain size of about 0.4 µm due to formation of deformation-induced boundaries within initial grains.
Large deformation of hcp metal was studied insufficiently; meanwhile limited number of slip system operating and twinning can be key factors influencing on microstructure evolution in Ti.
Based on the EBSD analysis the number of grain boundaries with the misorientation higher than 15° (high-angle boundaries) increases with the strain from 10% after first increment to almost 70% at the end of the deformation (after Σε=6.2).
At small strains microshear bands and twins are observed within the initial grains.
On the each next step of deformation some dislocation boundaries scatter to a large number of movable dislocations decreasing yield stresses of the material (Baushinger effect) [11].