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Usually, the average grain size of diamond film which is below 200 nm can be called nanocrystalline diamond film.
Corresponding with nanocrystalline diamond film, there is a kind of diamond film of which average grain size ranges from 0.3 um to several hundred microns called micron grain diamond film.
Meanwhile, the peak at 1332 cm-1 shifts to lower wave numbers and becomes wider, weaker and more asymmetric.
With these analysis, we can confirm that the main composition of the film is diamond, whose grain size is tiny.
According to the reported researches, compared to the characteristic peaks of the micron-diamond film the characteristic peaks of the nano-diamond film should shifted to lower wave numbers, while in the experiment they are consistent.

SSFSP is a solid-state process that uses a rotating tool plunged in the material to promote microstructure modification, mainly grain refinement, on the workpiece without melting the material itself.
The plate number 40 processed by 48 BOP.
The measured values of tool geometrical features of the used tool are absolutely very close to those of the parent one, allowing to assess that tool wear is negligible for the investigated number of BOP.
To compare the base material the BOP is characterized by a refined grain and homogeny microstructure due to the dynamic recrystallization.
Conclusions On the basis of the experimental campaign of 2880 BOP made with SSFSP process carried out on 4 mm thick AA 6082 T6 sheets, the following conclusion can be drawn: · The steel tool seems not suffer any wear, according to the fact that his dimensions remain constant as number of BOP increases; · Main surface roughness parameters chosen to describe BOP surface slightly decreases as number of BOP increases; · Only the Ra measured along the processing feed direction (namely RaL in the paper) increases; · Vickers micro hardness measurement performed along the cross section of some noticeable BOP (the first, the 1440th and the last, i.e. 2880th BOP) confirm that no variations occur in the properties of the processed sheets as the number of BOP increases.

Moreover, these authors homogenized the polycrystal response from the constituent grains without any predetermined grain interaction rule.
is extended to plastic anisotropy, the number of independent coefficients beside the exponent a is 8 and 16, for the plane (Yld2000-2d) and general (Yld2004-18p) stress states, respectively [20-21, 26].
The stress resolved on each slip system is calculated from the macroscopic stress applied on the polycrystal, the crystallographic orientation of the grain considered and an averaging scheme allowing the transfer of the macroscopic stress to local tensors for each grain.
For instance, a simple approximation due to Taylor is to assume that all grains deform uniformly.
In order to probe the yield surface of DP780, a number of biaxial deformation states were imposed.

The number of space node is 4000.
The relation used is a Kröner-Eshelby micromechanical model: (4) where is the mesoscopic elastic stiffness tensor of one steel bar, N is the number of austenitic grains per steel bar, is the volume fraction for each grain chosen equal to for an isotropic material.
is the microscopic elastic stiffness tensor for each austenitic grain.
Calculations have been performed for N = 10000 austenitic grains.
The number of time node is 1440 for duration of 4380 hours.

Scherrer's calculations were attempted to estimate average grain size [2].
Thickness of films obtained by spin coating depends upon the number of layers, that were kept constant.
In several studies c-axis oriented growth of wurtzite ZnO grains is seen.
But, in this study no such grain orientation is observed.
SHI irradiation causes greater agglomeration of grains which increases with fluence.

Worldwide, the interest for FSP is reflected by the large number of papers, articles, conferences, international symposium and patents.
However, the average grain size of the material plays a significant role in many applications.
The strength of the polycrystalline materials is related to the size of the grains so that their resistance increases with a reduction of the grain size [17].
In order to transform a metal with coarse grains into a material with smaller grains it is necessary to apply some techniques/processes that lead to obtaining the finishing of the granulation.
Langdon, Advances in ultrafine-grained materials, Mater.

The grains within the weld nugget are fine, with a roughly equiaxial dynamic recrystallized structure in comparison with the base material.
The grains in the region of TMAZ, depending on the alloy, may or may not exhibit signs of recrystallization.
However, FSW is also associated with a number of unique defects because of incorrect tool design and unsuitable welding parameters.
The weld nugget is composed of fine equiaxial, recrystallized grains, whereas the TMAZ is composed of coarse-bent recovered grains. [4,10] These figures indicate that the grains in the weld nugget are about 10–20 μm in size.
Optical microscopy verified that the grain structure in the region around the zigzag line of the root part of the weld was similar to that in the weld nugget.

Extrusion involves the formation of a strong strain localization zone, which influences the final product microstructure and may lead to a coarse grain layer close to the surface.
A coarse grain layer can occur close to the surface and this will lead to deterioration of the product mechanical properties [1].
This problem has been widely investigated by a number of researchers, see for example [1,4-9], and several possibilities regarding control of the shape of the dead zone by changing the die shape have been suggested.
One major issue is that when remeshing operation occurs during FE simulation, the number of mesh nodes, as well as the number of integration points, changes.
This shear zone influences the final product microstructure and may lead to a coarse grain layer close to the surface.

The number of inclusions is reduced by application of complex gating system and by leaving small amount of alloy in the cruicible after the pouring process.
Preparation of the microsections included: grinding on the SiC abrasive papers with gradation 320÷1200, polishing on the diamond pasts with grain size 3µm and 1μm as well as polishing on the Al2O3 suspension.
The inclusions had two morphologies: bulky particle and cracked layer covering the grains (Fig. 4b).
Complex gating system with ceramic strainers has to be applied to reduce number of inclusions. 5.
Application of feeders reduces number of thin film inclusions.

The grain size observed from the microstructure of AFM is around 50 nm and this indicates the aggregation of nanosize cryatallites.
The lattice constants a=3.2519 and c=5.2012 have been calculated from the XRD data for the ZnO thinfilm spin coated at 3500 rpm and is found to be well in agreement with JCPDS data file number 05-0664.
TC (hkl) = Ii(hkl)/I0(hkl) 1/N ∑Ni=1 Ii(hkl)/I0(hkl) (3) Where TC (hkl) is the texture coefficient of the (hkl) plane, Ii(hkl) is the measured intensity, I0(hkl) is the standard intensity of JCPDS power diffraction pattern of the corresponding peak and N is the number of reflection considered for the analysis.
The overall surface structure shows grains of spherical shape without any cracks and pores as shown in fig 7(a).
The grain size observed from the microstructure of AFM is around 50 nm and this is different from the grain size determined by using XRD, which indicates the aggregation of nanosize cryatallites.