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Figure 4 summarizes the counted number of voids over the size of about 1µm in the area of 400µm x 500µm around central region of the minimum cross section.
In both type of specimens, large number of voids are nucleated after large scale straining just before ductile cracking, whereas no remarkable increase of voids can be seen before such large straining.
Fig. 4 Evolution of number of voids observed around center of minimum cross-section.
Table 3 Comparison between average dimple size and average grain size after straining.
Fig. 7 Comparison between fracture surface appearance and deformed grains for both smooth and R2 specimens.

Pulse frequency and pulse number are 3 ~ 20 Hz and 5000, respectively.
The effect of the grain size on hardness has been studied and explained by some authors.
Grain boundary hardening and grain boundary sliding are two mechanisms of the possibilities to change the hardness of films [13, 14].
According to the Hall–Petch relationship, the hardness of materials increases with decreasing grain size.
On the other hand, softening of materials caused by grain boundary sliding is mainly attributed to the large amount of defects in the grain boundaries.

Both properties allow us a number of new innovative investigations which have been discussed elsewhere [1,2,3].
The number of exposures depends strongly on the texture itself.
A medium grained Ti 2.5 Cu was heated up till 875°C in steps of 25°C using a mirror furnace originally used for neutron diffraction.
Grain growth started explosively at 875°C so that only some large β-grains existed.
Acknowledgments This work has been funded by the German Ministry of Education and Research (BMBF) under the contract numbers 03BRE8CL and 05KS1MCA/2.

The difference of sub-granular (or small-granular) structure from the fragmentary one is that grains as a rule are limited by large-angle boundary (grain-boundary angle is more than 6 degrees), and the fragments differ with the small-angle boundaries (grain-boundary angle is less than 6 degrees) [8].
With the development of fragmentation the number of grains (fragments) is increased in the unit of square, in the result of which the diffraction picture changes (one should take into account, that each fragment gives its reflection).
If it increases and the fragments are closer by their properties to micro-grains, micro-diffraction picture is closer to the circular one.
On the contrary, if the grain-boundary angle remains small, micro-diffraction picture remains pointed containing one or few planes.
The reason for that phenomenon is that the boundaries of deformed origin absorb quite more number of dislocations than the boundaries of thermal origin do.

The fatigue data of the three types of miniature specimens are plotted as maximum nominal cyclic stress vs. number of cycles and shown in Fig. 2.
The supersaturated γ-Ni matrix grains are elongated in the build direction, Fig. 3c.
On the plane perpendicular to build direction, polyhedral grains were observed (Fig. 3d) and they correspond to the cross sections of the elongated grains.
a) b) c) d) Fig. 3 Microstructure of SLM Inconel 718: a) specimen A, plane x-z, LM, b) specimen B, plane x-y, LM, c) elongated grains with white Laves phases on grain boundaries, x-z plane, SEM, d) polyhedral grains with white Laves phases on grain boundaries, x-y plane, SEM.
Observed differences consist in number of initiation places according to the longitudinal specimen direction with respect to the build direction.

However, too low feed rate will make a large number of abrasive particles drop from binder, which worsens the wheel topography.
Abrasive water jet is a new clean and high efficiency technology.[4]It has also been reported to be used for dressing wheel. [5] There is no mechanical damage of grains and tool wear which can’t be avoided in conventional mechanical dressing methods.
There is no limit on the kind of binder and the size of grains in the abrasive water jet dressing.
(1) Diamond grits of a worn grinding wheel are protruding from bond and the distribution of the abrasive grains becomes uniform after dressing with high pressure abrasive water jet
Too low feed rate will make a large number of abrasive particles drop from binder, which worsens the wheel topography

The number of reports dealing with HECs has increased rapidly in recent years, offering strong evidence for the timeliness and global technological character of this research sector.
Because of the small difference between the average grain size of the samples during the indentation, many imprints are located at the grain boundary.
In general, the hardness of the grain interiors (indent C) is similar for different grains (indents A, B).
The presence of the imprints on the grain boundary has an influence on the mechanical response of a grain indented in the vicinity of the boundary.
The Young’s modulus of the grains and grain boundaries were very similar with value of approximately 570 GPa. 4.

The range of welding conditions were decided based on the large number of experimental trails.
The fusion zone microstructure showed the formation of mixed grains of larger and fine grains zones at lower welding speed and currents.
The increase in heat input in the welds leads in the formation of larger grains especially at the welding current of 120 A. the presence of single enlarged grain in the fusion zone may be one of the reason to decrease in strength of the joints.
The microstructures at higher welding current and speed are showed finer grains and with the less number of enlarged grains.
The presence of larger grains in the welds at lower welds are gradually decreased with the increase in current and formed maximum number of finer grains where the high strength achieved.

Sample N50 in Fig. 2c has smaller grain size of 36.93 nm.
The N50 grains did not uniformly distribute on the surface as in N100 and N75 but these small grains are grouped together and seem to form larger grains.
The first shell coordination number (Ti-N) of about 6-7 and the second shell coordination number (Ti-Ti) of about 10-14 for sample N100 and N75 are in agreement with the ideal value (6 and 12 for Ti-N and Ti-Ti respectively).
TiN local structure of N50 has high mismatch of coordination number comparing with TiN perfect crystal.
Surface morphology from FE-SEM indicated small grain size for TiN phase and large grain size for Ti phase.

As sintering time and temperature increase, total porosity and specific area decrease (Fig. 1b), the latter containing information on both porosity and grain size.
For instance, for an identical porosity, it is possible to obtain coarser grains by sintering for a longer time.
At the micropore and grain scale, fracture proceeds by an intergranular mechanism, resulting from the fracture of individual sintering necks (Fig. 2c).
Models of the second category usually yield more complex equations; one has been chosen here because of its relative simple expression, because it proved to be efficient in describing the evolution of mechanical properties of many sintered materials -metals, glasses and ceramics- as a function of porosity, but also because it is based on an actual stereological description of the microstructures for different initial stacking geometries [5,6]: Mp = M0 [Nc(1 - p) - (Nc - 1)(1 - p) 2/3], (2) where Mp is the mechanical property of the porous material and Nc is the average coordination number, i.e. the number of neighbouring grains of each grain within the microstructure.
Indeed, these ceramics, even if sintered from a pressed powder, cannot be considered as a simple stacking of grains, since there are macropores.