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At the same time, it is shown that fatigue cracks and their growth can be influenced by microstructural features – like grain boundaries - because these can act as barriers.
During transformation the prior austenite grain is divided into bainitic packets consisting of several bainitic blocks which in turn consist of ferrite laths and retained austenite [3] similar to the structure that was already reported for lath martensite [4].
This is due to the higher austenitizing temperature, which leads to larger prior austenite grains as well as larger crystallographic bainite blocks.
Results of the calculated Kblock are plotted against the number of cycles to failure (Figure 2b).
The fact that both types of austenitizing temperatures are mixing together shows that the formation of two trends is not directly depending on the prior austenite grain size.

The first superalloys have polyedric microstructure consist of gamma solid solution, some fraction of gamma prime and of course grain boundaries.
On the other hand, wrought superalloys metallography evaluates the grain boundary and deformation, as well as crystallization twins.
For all fatigue tests were number of cycles Nf = 107 considered as fatigue lifetime limit sc.
Microstructure of wrought superalloys consist of polyedric grains of various size, depends on mechanical working.
On the other hand, wrought superalloys are prepared with aim to reveal grain boundary and grain size.

Natural, river aggregate "Moravac" with the grain size between 0/4 mm (river sand) was also used.
For this purpose, three different concrete mixes were designed: reference concrete (marked as mixture number "1") with 0% of recycled tire aggregate, mixture number "2" with 10% and mixture number "3" with 20% of waste rubber content in relation to the total mass of aggregate.
Considering the fact that the diameter of rubber grains ranged between 0 - 4 mm, and that any additional cutting was not possible, these grains were only dried in the oven before the test.
Most part of the applied recycled rubber aggregate (even 71.6%) had grain size between 1 and 2 mm [12].
The criteria for evaluation of the obtained testing results are related to the number of blows before the appearance of the first crack (N1), as well as the number of blows required to break the specimen (N2).

Structure and Properties of Ultrafine-Grained Cu-Cr Alloys after High Pressure Torsion D.V.
Introduction Severe plastic deformation (SPD) is well known now as a method to obtain ultrafine-grained materials with principally new physics-mechanical properties [1,2].
In a number of studies [3-8], the SPD method applied to widely used low-alloy chromium and zirconium bronzes was shown to improve their mechanical properties and thermal stability.
After HPT the sizes of structural elements in grain-subgrain structure of Cu-0.75% Cr alloy were 100-200 nm for both initial states.
After HPT the sizes of structural elements in grain-subgrain structure of Cu-0.75% Cr alloy were 100-200 nm for both initial states.

The most considerable change in the bandgap, grain size and Te/Cd ratio were 1.54 eV to 1.66 eV, 40nm to 15nm, and 56/44 to 60/40 respectively.
, Ii, the intensity of a generic peak in the XRD spectra, I0i, the intensity of a generic peak for a completely random sample and N is the number of reflections considered in the analysis.
As one can see from this figure, the accumulation of crystallites in the samples is different from one sample to another.The most considerable change in the grain size is observed from 40nm for S1 to 15nm for S4.
The difference in the crystallite size calculated using XRD data presented in Table 1 and the grain size observed by a direct method such as FESEM would not be surprising, due to the errors encountered in Debye Scherer method for estimating the crystallite size [6].
The significant increase in absorption coefficient of S7 might be due to increase in its Tellurium content in comparison with S1 (Table 1), along with its specific surface morphology which presents discrete groups of small grains (Fig. 3) and higher preferential orientation factor of this sample.

In the present work, these steel master alloys were atomised via a vacuum inert gas atomisation to provide fine grain sized metal powders for the assembling of TRIP-Matrix-Composite.
Steel master alloys are atomised to provide fine grain sized steel powders for the final sintering of Metal Matrix Composite (MMC).
It is well known, that spraying parameters, such as gas pressure and the thermophysical properties of liquid steel phase, affect powder grain size distribution [2–4].
Moreover the 16-7-3, -9 alloys have less coarse grains, the maximum of fine grain sized particles increases compared to the reference material AISI 304.
According to Kishidaka the mass median particle size distribution dm for a two beam atomisation is calculated from dimensionless parameters, the Weber (We) and Reynolds (Re) number, and the mass ratio of gas jet flow rate to metal flow rate .

FESEM analysis showed that the grain size and porosity increased when the heat treatment increased.
FESEM analysis in Fig. 2 showed that grain size and porosity increased when the heat treatment increased.
It is well known that the addition of a few percentage of P2O5 to silicate glass compositions, promotes the volume nucleation and glass-ceramic formation [7] that effected the grain size and porosity of sample increased at 850°C and 950°C is clearly shown in Fig. 3.
The effect of heat treatment on SNCP glass-ceramic increases the number of peaks, increasing the intensity of peak, changed the crystal system, and formed new peaks.
From the observation of microstructure, grain size and porosity increases as the heat treatment of samples increases.

The process of microstructure evolution during remelting includes spheroidization preparation, grains fining and spheroidizing, and grains growth.
The microstructures of preformed AZ91D alloys changed from compressed textures to polygonal grains and then to spherical grains.
When deformation rate increased to 30, grains had got rounder and rounder, however, average dimension of grains increased, fluidity got poor.
When remelted temperature and holding time were constant, with the increment of number times of extrusion the crystal grain became small [39].
Grain evolution in conventional and rheocasting[A].

The settling basin consists of 6 chambers, numbered 1# to 6# from left to right, every two chambers make up a set, hence 3 sets altogether.
(1) Settlement similarity For a normal model, it is required The sediment grain size scae is calculated with Dou Guoren derivation relation[2]: The coefficient varies with the change of the grain Reynolds number.
Of the prototype inflowing sediment, that of grain size 0.07mm~0.25mm makes up 84%, with medium particle size of 0.125mm, so takes the value of 0.82, and
The result showed that, under the experimental water and sediment condition, during the initial stage of the settling basin operation, the total sedimentation rate ranged from 32% to 38%, and that of the sand of grain size larger than 0.25mm was between 80% and 91%. 3.4 Sand canal desilting test (1) Sand canal flushing flow The settling basin was continuous wash type, each of the settling basin chambers was equipped with desilting segments at the bottom, each segment was 30m long with 58 openings of 0.19m × 0.2m each, and under each chamber there was a sand canal.
Under the experimental water and sediment condition, the sedimentation rate of sand of grain size over 0.25mm ranged from 80% to 91%, which did not meet the design requirement.

Although thermal annealing slightly increases the apparent grain size, the structural changes induced by thermal annealing cannot be clearly shown by SEM analysis.
Since the FWHM of the diffraction peak is inversely proportional to the grain size of the film, XRD analysis indicates that while the crystallite size of the (002)-oriented grain is invariant, the crystallite sizes of the (100)- and (101)-oriented grains increase slightly with thermal annealing and with increasing annealing temperature.
The increase in intensity of the D 0A 0 luminescence was attributed to the increase in the number of vacancy related donors [10].
Therefore, it is expected that the enhancement of the band-edge peak intensity by thermal annealing at 900 o C�is due to increased concentration of vacancies in GaN and due to reduction in the number of non-radiative recombination centers in ZnO.
SEM indicated that the top-view grain size increases slightly as a result of thermal annealing.