Search results

The minimum grain size was considered to be 27 voxels.
Angle θ displays the orientation of the long axis of the grain with respect to the RD and (d) quantification of the number of grains with long axes oriented at different angle with respect to the sample RD.
The grain shape of each individual grain was approximated with an ellipsoid (Fig.4a).
After applying both cleaning methods, the total number of grains remaining from the scan was 215.
RD and TD oriented grains).

The segregation at the free surface was found to be stronger than the segregation at the grain boundary.
Cu bicrystals containing deliberately made internal cavities at the grain boundary were doped with Bi, annealed at temperatures between 1073 and 1223 K, and broken along the grain boundary in an ultra-high vacuum chamber for AES.
Using the equilibrium Bi vapour pressure and applying the ideal gas equation, the number of Bi atoms present in a cavity at a certain temperature can be estimated.
Conclusions Using a special method to produce Cu bicrystals, containing a grain boundary with cavities at the grain-boundary face, the segregation of Bi in Cu simultaneously at the grain boundary and at the free surface (of the cavities) was investigated under identical experimental conditions.
McLean: Grain boundaries in metals (Clarendon, Oxford 1957), p. 116

Reported in the literature[8], with the increase of the content of Ca, Mg17Al12 reduced gradually, the number of Al2Ca increase gradually in Mg-Al-Zn alloy.
In the solidification process, because of its solution capability in magnesium alloy is quite poor(maximum 1.6%), Ca easy to be pushed into the forefront of α crystal grains, formed a layer of Ca-rich metal film in alpha grain interface, which hinder grains growth.
When Ca reaches a certain level in the alloy, it will form high-melting-point Al2Ca phase with Al, the phase precipitate on grain boundary also to the benefit of inhibit the growth of grains.
Moreover, the supersaturated alloying elements in the matrix precipitate and form new second-phase particles, large number of tiny Al2Ca and MgZn2 dispersed evenly in the alloy, they are mainly located in dislocation, grain boundary or uniform distribute in the tiny equiaxed grains[10].
The smaller size, the greater the number, the more uniform distribution of these second-phase particles, the more contribution to the intensity.

The entire reaction can be expressed by Yamamoto’s equation because it contains the term of particle number.
He thought that the particle number exponentially changes in natural phenomena [5].
He introduced the particle number at time, which is expressed as follows [4]
The decreasing rate of the particle number is expressed by the following equation
The parameters, and in the term of the particle number are greater than and.

And then the tartary buckwheat grains were harvested after autumn.
Finally, it was recorded that the yield of seedlings and grain, the thousand grain weight.
Data collection concluded height, branch number, flower number, leaf area, above ground biomass and grain yield at floral initiation period and the beginning of florescence with higher content of rutin suitable for the regeneration of buckwheat seedlings.
According to Table 3, plant height, leaf size, branch, flower number and biological yield and buckwheat production of different varieties varied greatly.
Number of flower clusters and branch number mainly affected tartary buckwheat grain yield. 

Today, a numbers of research have shown that the Mo-10Nb alloy was used as a sputtering target, which the following law must be met: (1) high purity, (2) high density; (3) high homogeneity of components and microstructure[5-6].
As can be seen from the Fig.2 (a, b), the grain size of Mo-10Nb alloy material through non-pressure technology preparation have a wide rang of distribution, a larger number of grain size is 30μm ~ 50μm, however there are a few grain size reaches 70μm.
The phenomenon of grain growth was discovered, according to the Fig.2 (a).
The grain size of Mo-10Nb alloy materials by hot pressing technology preparation have characteristics small and completely distributed, the values of grain size are within the range of 20μm ~ 30μm.
In addition, the sample by non-pressure sintering technology preparation own a large gap and a larger number of large size, resulting of lower density than samples by hot sintering method.

At 150oC, the crack mainly progresses at grain boundaries of recrystallized grains.
The fatigue life was defined as the number of cycles in which the maximum load was reduced by 20%.
This means that fracture occurs in grains and grain boundaries so that the fracture mode is the mixed mode of transgranular and grain boundary fracture.
Since the number of the origin of the crack is relatively large, fatigue lives degrade at 150oC in the Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge alloy in which fracture mainly occurs in the grain boundary.
Although most of recrystallized grains formed at 150oC has misorientation of 5-15o, several recrystallized grains have high angle grain boundaries which misorientaion are over 15o.

Thermal Stability of Ultrafine Grains in Al-Fe-Mn-Si Foils Prepared by ARB and Subsequent Rolling P.
UFG sheets exhibit enhanced strength and very fine grain structure.
No significant difference in the hardness changes due to annealing is observed between the ARB foils differing by the number of cycles (4 or 6 cycles).
Such an unusual phenomenon is attributed to the decrease of the number of dislocation sources during annealing that is observed in highly deformed alloys.
It is well known that CReX occurs in materials of small grain size after large strains [8,9,10].

Design cycle of the Laval nozzle Grid Ultimate design Initial design Model building Flow field number modeling Modifying Model building and grid.
The initial grain size is in the range of 0.2-0.5um.Fig.7. shows the TEM micrographs of nano-structured layer (about 3um thickness) of the sample.
The average grain size in the surface is approximately 20nm.
From the dark field image, one can see nanoscale grains of which the shape is roughly equiaxed.
These grains possess random crystallographic orientations, as indicated in the selected area diffraction (SAD) patterns.

The number of atoms sitting in or affected by the grain boundaries is indeed rapidly increasing: for instance in a 20nm sample this amounts at least 10% of the atoms.
Two type of samples are used in this study: (1) a selfsimilar structure having 15 grains with mean grain sizes of 5, 12 and 20 nm and (2) a sample with 125 grains with a mean grain size of 6 nm.
A sample with 125 grains and a mean grain size of 5nm was choosen.
A large number of grains are necessary in order to minimize the effects imposed by the periodicity used to simulate bulk conditions.
The small grain size is chosen to reduce the total number of atoms in the sample (to 1.2 million) so that longer deformation times are possible at acceptable strain rates.