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Anisotropic behaviour of grain boundaries V.
The number of papers containing data on different grain boundaries is very limited.
A large number of good quality bicrystals is needed for such measurements and their preparation is a substantial obstacle to be overcome.
Grain Boundary Segregation Diagrams.
The enthalpy of segregation derived from such measurements on sufficiently large number of samples is a better characteristic of segregation than the enrichment factor that depends on the thermal history of the sample.

For interface controlled abnormal grain growth there may be a number of processes associated with atomic attachment at the interface that can be the controlling mechanism.
In the past decade, a number of researchers have invoked the idea of a non-linear relationship between driving force and grain boundary velocity to explain abnormal grain growth during nucleation limited interface controlled grain growth.[8-10,19-20] A schematic of this is shown in Fig. 4.
The nucleation limited interface controlled abnormal grain growth mechanism has been invoked to describe abnormal grain growth in single phase and pseudo-single phase systems.[16,21] Systems where only a small number of the grain boundaries contain a nanoscale intergranular film may be considered to be pseudo-single phase.
If the grain with the defect can not grow any faster than the normal grains then this grain can not grow abnormally.
Arrhenius behavior has been observed in alumina in a number of studies, where the driving force varied with temperature.[4,26,29-31] It then remains to explain how abnormal grain growth occurs by a diffusion controlled mechanism in pseudo-single phase alumina.

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.

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.

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.

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.

%P) by refining grain size.
Microstructural evolution of the copper alloy with the number of the 3-layers ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy (TEM), and electron back scatter diffraction (EBSD).
Results and Discussion Tensile properties of Cu-0.02P alloy (phosphorus deoxidized copper) as a function of number of 3-layers ARB cycles have been shown in Fig. 2.
Tensile strength of the specimen processed by the 2-layers and 3-layers ARB increased with the number of cycles.
A large number of dislocations and cell structures were observed in the samples after 3 cycles.

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.

Here, a continuum microstructure is bitmapped onto a 2D square lattice, initially taking the form of a matrix populated with random numbers ranging from 1 to Q, with Q representing the number of probable orientations shown by the grains in the simulated microstructure.
At this juncture, a random number (r) is generated which is uniformly distributed between 0 & 1.
Fig 10 suggests the relationship of R(lim) with the percentage of particles (φ) interacting with the grain boundaries, in simulated microstructures. φ was computed, through coding, by counting the number of impurities physically in contact with the grain boundaries.
The number of MCS which resulted in grain growth stagnation is also given alongside and it peaks at KTs=0.4, the critical temperature.
They clearly demonstrate (i) the log-normal behavior of the grain sizes atFig. 12: Grain Size Distributions for pinned regimes at different values of KTs, at N=1000, Q=64 and f=0.1 various values of KTs, and (ii) that the number of grains at stagnation dwindles as KTs are increased, because of enhanced grain growth.

Development of GBS was experimentally observed during plastic strain of a number of UFG metals including copper [[] R.Z.
Most of grains coarser than 6 mm are elongated but due to their limited number they effect on the average grain aspect ratio weakly.
The number of twins does not rise.
In this case, the grain appears severely curved and a great number of straight dislocation glide lines are observed inside the grain.
Despite the limited number, coarse grains may occupy a noticeable part of the sample volume (0.27 and 0.46 prior and after tensile test, respectively).