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But due to the complexity of CVD process, a large number of defects such as pores, mosaicity and dislocation were found in SiC coating.
As shown in fig.3-b, the grains were found to be faceted columnar with 0.65µm and range closely.
So the grains size was larger and the coating with coarseness surface was obtained.
This was maily due to that the grain growth direction was different with the process parameter fluctuation.
At lower temperature, the grains mostly were fine with equiaxed structure and low dense but the grains were bigger with faceted columnar and close-packing when temperature rose to 1230°C.

While depth resolutions of a few 100 micrometres can be achieved with narrow beams, the grain size of the studied material often prevents a conventional analysis of diffraction rings with such high resolutions; however, strategies for improving grain statistics can often be applied in such cases.
However, in many cases, only moderate depth resolutions are required, and with a larger beam cross-section, the grain statistics can be improved.
The grain size of the material was small enough to yield homogeneous diffraction rings with this gauge volume.
Since beam intensities are much higher than at neutron instruments, a large number of points can be measured within short time.
Moreover, in many cases measures have to be taken to improve the grain statistics.

We speculated the possible reason was resulted from the pits be etched continuously and then the micro-pillar structures is randomly spread on the CVD diamond grain facets.
Even more the grain facets were almost disappeared.
But owing to a large number ions bombard on the coated surface in the RIE process, the partial gold film can be removed in short time.
Therefore, Fig.3(c) shows a lot of irregular microstructure on the etched grain.
We deduced that phenomenon mainly resulted from different etching rate between the gold masks and diamond grains.

Therefore major numbers of studies have been made on this subject using different approaches [1-4].
In such studies [2-5], different carbide additives (Cr3C2, VC, TaC, NbC, TiC) were used in order to suppress the growth of tungsten carbide grains and improve hardness and wear properties.
The cobalt in the system forms a strong interconnection between WC grains as a result of a liquid phase sintering.
Hot pressing method was preferred for densification to protect the grain size of WC particles from enlargement during sintering process and to achieve products denser than those produced by pressureless sintering [1,2].
EDS analysis of the grey phase has shown that it contains some amount of Co which is less than binder area and some amount of W which is less than WC grains (Fig. 4).

It was showed that: (1) the single-pulse deposition zone presents irregular spattering shape and the phase of coatings was made up of TiC0.51N0.12 spherocrystal and dendritic crystal, Ti0.80V0.20 and C, (2) metallurgical bond between coating and substrate is realized, (3) the Ti(CN) ceramic particle, whose average grain size is 626nm, distributes dispersively among the coating and is in-situ synthesized by the reaction among titanium from the substrate, carbon from the graphite electrode and nitrogen from the shielding nitrogen gas.
The TiC0.51N0.12 phase appears spheric and dendritic grain.
The average size of the crystal grains was determined to be about 626 nm.
The number of the fund is E2007000566.

The microstructure especially the size, shape, number and distribution of precipitate, together with the strain hardening exponent n value at different strain range during plastic deformation of the Al-0.9Mg-1.0Si-0.7Cu-0.6Mn alloy sheet, subjected to different heat treatment were investigated.
(1) Where: N= the number of data sample, i.e., the selected calculating strain point number from the calculating strain range, and N≥10, εi= the instantaneous true strain relevant to the calculating strain point, and σi= the instantaneous true stress relevant to the calculating strain point.
Afterward, as the deformation of the alloy sheet increasing continuously caused by the multiplication and slipping of dislocations, the dislocations interacts and tangles with each other, or interacts with the alloy-phase particles and grain boundaries in the matrix of alloy sheet.
As the strain of T4 alloy sheet approaches 20%, the flow stress is close to the fracture stress of alloy sheet, the initiation of micro cracks from high stress concentration zone, such as the cell walls of dislocation substructure or the dislocation accumulation groups at the grain boundary or in the front of the big alloy-phases is the main reason for the further descending of stage strain hardening exponent ns and the macro strain hardening effect of T4 alloy sheet.
After the plastic deformation exceeds 1% due to much more dislocation glide, new dislocations are created by tensile load and must interact with both those dislocations and the precipitates or grain boundary already existing in the matrix of alloy sheet, which cause the dislocation tangling and dislocation accumulation groups at the grain boundary or in front of the precipitates.

A large number of aluminum alloys (greater than 30%) in the automotive can achieve the overall lightweight effect.
Under a certain test condition, the formula for the spring-back can be empirically summed up according to the relevant test variables and a large number of test results.
The size of the grain will obviously affect the inhomogeneity and the emergence of the texture.
Coarse grains are more prone to yielding uneven deformation, grain rotation and texture than fine grains, resulting in the formation of orange peel after the deformation of the aluminum alloy.
It is pointed out that the grain size has some influence on the roping phenomenon, and the roping phenomenon is less likely to occur when the grains are evenly distributed and their sizes are moderate.

The research was carried out on the erosive wear under the influence of alundum particles (grain size of 0.6 - 0.7 mm) striking the coatings at the angle of 45 degrees.
Essential influence on the erosive wear intensity has a coating thickness (number of layers).
The author obtained the increase of erosive wear resistance as well as scratch resistance of acrylic coatings as a result of adding to their composition copper nanoparticles (3.5% wt.) of 66 nm mean grain size [17].
Particles of granulated alundum of grain size 0.60 - 0.71 mm (according to the Polish Standard PN-76/M-59111) have been used as the erosive material (Fig. 2).
The study was conducted on erosive wear of acrylic coating under the influence of alundum particles (grain size of 0.6 - 0.7 mm) striking the coatings at an angle of 45°.

XRD analysis shows that SnS thin films were polycrystalline and had orthorhombic structure, and SEM micrographs reveal that SnS thin films were densely packed surface coverage and consists of large flowerlike grains.
With the increase of annealed temperature, the peaks were quite sharp and intense, indicating that the grain size was large.
The XRD profiles indicated that SnS crystal grain has a preferred orientation at (111) plane.
SEM photographs of SnS thin films with different annealed temperature (a)200℃,(b)300℃,(c) 400℃ With the increase of annealed temperature, the surface morphology of the samples becomes more smooth and homogeneous, and the big aggregate particles in Fig.2 (a) gradually decreases and aggregate grains were not obvious in Fig.2 (c).
Acknowledgement This work was partially supported by Key projects for National Natural Science Foundation, China (grant number 51032005), and supported by State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (Wuhan University of Technology).

Several specimens of powders, differing in type and grain size, were obtained by treating these source samples.
Then in order to provide specimen with homogeneous grain size, the powders have been diluted in alcohol and sieved using sonication; a series of four metal filters in a column of an ultra-sound wet-sieving apparatus was used for this mentioned purpose [2].
The raw data collected at the BM16 of ESRF were preprocessed to check the standard accuracy of the goniometer; to correlate differences between the Sample Grain Size 2���� fit FWHM Fit FWHM diff d � d a � a (10-2) h k l NIST640b 5 µm < D < 10 µm 14,658 1,25 0 (a) 3,1359 0,0053 (1) 5,4316 0,75 (1) 1 1 1 14,659 0,94 0,31 (a) 3,1357 0,0040 (1) 5,4312 0,57 (1) 1 1 1 MWm30 D < 30 µm 28,282 1,03 /// 1,6374 0,0012 (1) 5,4307 0,17 (1) 3 1 1 49,252 1,21 /// 0,9600 0,0004 (1) 5,4308 0,18 (1) 4 4 0 14,66 0,86 0,39 (a) 3,1355 0,0037 (1) 5,4308 0,52 (1) 1 1 1 MWf20 20 µm < D < 30 µm 28,282 0,93 /// 1,6374 0,0011 (1) 5,4307 0,15 (1) 3 1 1 49,253 1,17 /// 0,9600 0,0004 (1) 5,4307 0,17 (1) 4 4 0 14,66 1,12 0,13 (a) 3,1355 0,0048 (1) 5,4308 0,67 (1) 1 1 1 MWf10 10 µm < D < 15 µm 28,282 1,35 /// 1,6374 0,0015 (1) 5,4307 0,22 (1) 3 1 1 49,252 1,51 /// 0,9600 0,0006 (1) 5,4308 0,22 (1) 4 4 0 14,658 2,42 1,17 (b) 3,1359 0,0050 (2) 5,4316 0,70 (2)
Individual segments containing a limited number of peaks have been isolated from the whole diffraction patterns in order to care as much as possible peak shapes and tails representations.
The above mentioned Table 1 reports the grain size related to each specimen, the peak index [hkl], the peak position and FWHM of the profile fit s from the specimens of this work and the FWHM of data from the specimen “NIST640b”.