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Introduction Migration of grain boundaries during grain growth generally proceeds under the capillary driving force provided by the boundary energy owing to a reduction of the total grain boundary area.
Due to the difference of susceptibility parallel and perpendicular to the c-axis with || > ||, the direction of the driving force pm was from grain 2 towards grain 1 (Fig. 1).
Mean grain size, number of grains and fraction of different grain subsets after annealing at 340°C for 90 min as obtained by orientation microscopy (EBSD in a SEM).
Field Total number of grains Subset Mean grain size, µm Number of grains Grain fraction both 82 1285 0.67 0 T 1925 (90°,20°,φ2) 81 656 0.34 (270°,20°,φ2) 83 629 0.33 both 100 1298 0.88 17 T 1471 (90°,20°,φ2) 99 444 0.30 (270°,20°,φ2) 100 854 0.58 As seen in Fig. 4, the magnetic annealing resulted in an asymmetry of the two major texture components.
Summary Magnetically induced migration of planar <> tilt grain boundaries in zinc bicrystals was measured, the absolute values of grain boundary mobility were obtained.

The structural changes can be characterized by the evolution of many mutually crossing kink bands at low strains followed by increase in their number and misorientation, finally resulting in a fully developed fine-grains at high strains.
The total number of boundaries was 80 to 100 in each sample.
This leads directly to the evolution of a new fine-grained structure with medium-to-high angle grain boundaries.
The numbers in insert indicate the misorientations in degrees. 20 40 60 80 0.1 0.2 0.3 0 Misorientation angle,θ /deg Frequency, AZ31 T=463K Σ ε =3.2 θ =38° ε =3× 10 -3 s -1 fkink bands as well as full development of new grains hardly take place even at high strains [8].
The misorientation and the number of boundaries of kink band rapidly increase with deformation, finally followed by the evolution in-situ of new grains with high angle boundaries in high strain

Lineal intercept procedure is:（1）Estimate the average grain size by counting(on the ground-glass screen, on a photomicrograph of a representative field of the specimen)the number of grains intercepted by one or more straight lines sufficiently long to yield at least 50 intercepts.
An intersection apparently coinciding with junction of three grains should be scored as;（3）Calculation： Mean lineal intercept length： (1) 一Length of a test line, unit for mm； —Mean lineal intercept length； — Magnification used； 一 Number of intercepts with a test line； 一 Number of intercepts per unit length of test line。
All specimens grain-size number is in Table 3 and Fig. 4 HAZ Heat input（KJ/cm） Average grain-size number Mother material —— 11.0 ICHAZ 5 9.5 10 9.5 15 10.5 CGHAZ 5 5.5 10 5.0 15 6.0 ICCGHAZ 5 6.0 10 6.5 15 6.0 SCCGHAZ 5 5.5 10 6.0 15 5.5 Table 3 Grain-size number of HAZ Fig. 4 Average grain-size number of HAZ It is obvious from the ferrite grain size of mother material in the Table 3 that SMA490BW corrosion resistance steel has ultrafine grain size, while the size of the grain has decisive impact on metal's machinery properties such as tensile strength, toughness, plastic and so on.
As is shown in Table 3 and Fig.4：the grain-size number of ICHAZ is the highest, according to GB/T 6394-2002, the higher grain-size number is, then smaller grain size is, so grain size of ICHAZ is the smallest.
The reason is that the peak temperature of the ICHAZ is the highest and after high temperature heating, austenitic grain has significant trend to grow up , so after cooling , austenitic grain becomes bulky; in ICHAZ and CGHAZ, the grain size increases with the heat input increasing as is shown that when E=15KJ/cm the grain-size number is the lowest, this is because more welding heat input is in grain growth’s favour; grain size of ICCGHAZ and SCCGHAZ is smaller than CGHAZ is because that second thermal cycle have good role in fine grains.

The grains became thinner and elongated to the rolling direction with increasing the number of ARB cycles.
In addition, the fraction of high-angle grain boundaries increased with the number of ARB cycles and reached about 0.7 after 8 cycles.
Figure 4 shows the variation of mean spacing and the fraction of high-angle grain boundaries with the number of ARB cycles.
Summary The grains became thinner and elongated to the rolling direction with increasing the number of ARB cycles.
In addition, the fraction of high-angle grain boundaries increased with the number of ARB cycles, reached about 0.7 after 8 cycles.

Grain Boundary Surface Tension, Segregation and Diffusion in Cu-Sn System Gershman Evgeny 1,a and Zhevnenko Sergey 1,b 1 Moscow State institute of steel and alloys (Technological University), 4, Leninsky pr., Moscow, 119049, Russia a av14746@comtv.ru b sergeyng@mail.ru Keywords: Grain boundary tension; Grain boundary adsorption; Free surface tension; Zero creep method; Grain boundary diffusion Abstract.
Today is a lack of such data due to the limited number of the measuring methods.
The average grain size was 115 µm.
It is possible to evaluate the number of sites in surface monolayer A A m N N V n 3 2 max −       = (3) where Vm is the tin molar volume and NA is the Avogadro number.
Isotherms of surface tension and adsorption in Cu-Sn system: a,b - for free surface; c,d - for grain boundaries From the data obtained it is possible to evaluate the Cu selfdiffusion coefficient in Cu and Cu-Sn alloys using the relation of Borisov et. al. [9]: (6) where DGB is the grain boundary diffusion coefficient; D is the bulk diffusion coefficient; a is the mean distance between the atoms in the GB (approximately equal to the lattice parameter); γGB is the grain boundary surface tension; NA is the Avogadro's number; Т is the absolute temperature; R is the gas constant.

In this paper, hydroxyapatite was used as a grain growth inhibitor additive to get nano-titania ceramics with different grain size, and the effect of grain size on the bioactivity was studied in vitro.
In this paper, hydroxyapatite was used as a grain growth inhibitor additive to get nano-titania ceramics with different grain size, and the effect of grain size on the bioactivity was studied in vitro.
Ltd, China) were used as grain growth inhibitors.
The result of MTT assay showed that the number of viable cells was not statistically significantly different between the HT and the control (HA) (p<0.05), but the number of cells on the MT was much lower than the number on the control (p<0.05).
Both HA additive and the grain size of HT might be responsible for the bioactivity of HT.

Grain Size Analysis.
A circle was drawn on the image, the grains that were located entirely inside the circle were counted and then the grains intercepting the circle were counted separately and the average grain size was calculated by using the following formula: n1 = number of grains completely inside the test circle n2 = number of grains intercepting the circle NA = f [n1 + (n2/2)] f = Jeffries multiplier (magnification2/circle area) A = Average Grain Area (A = 1/NA) d - The average grain size d is defined by d = (A)1/2 G = 3.322(Log A) – 2.955 G is the ASTM grain size number (Note that NA is the number of grains/mm2 at 1X) Fig.2, shows the analysis and quantification of grain size by Jeffries planimetric method Total Grain Counting Method.
The numbers of grains were counted by hand and the total surface area of the tube cross-section was also calculated.
Then the total number of grains was dived by the area of the tube cross-section to give the average grain size in millimeters squared.
So the grains within the structure re-crystalize into many fine grains.

On the one hand, conventional optical analysis of the grain size distribution and neighbour numbers and on the other hand in-situ, high resolution continuous observation of microstructural development at high temperatures coupled with construction of time dependent crystallographic maps of the observed 2 dimensional polycrystal during grain growth.
The optical analysis allows large statistics but is limited in the number of characteristics that can be analyzed.
(a) (b) (c) Figure 3 The mean number of neighbours (S) of grains versus their relative area S/ from (a) optical experiments, (b) data from in-situ experiments at Tmax = 480 °C and (c) data from in-situ experiments at Tmax = 500 °C Several features that are not in accordance to the general theory of grain growth by von Neumann and Mullins which assumes isotropic grain boundary energy and mobility are observed.
These are: 1) The von Neumann-Mullins is not always satisfied (Fig. 4) Figure 4 Analysis of individual grains before and after heat showing the number of neighbours N versus change in grain area dS/dt.
Tmax = 480 °C, theat = 30 min., scale bar = 40 µm A) before heating, B) after heating. 6) Relative increase in number of grain boundaries that form traces of low index planes with heating.