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The object of the current investigation is a coarse-grained aggregate powder produced by sintering of a fine-grained powder mixture, crushing and sieving.
The method offers additionally the possibility of lowering the computational effort by generating smaller groups of particles but many of them, since the effort of simulating a large number of interacting particles increases superlinearly with the number of particles, but the effort to simulate several independent groups of particles only linearly with the number of groups.
The number of peaks np was observed to be mainly between 3 to 5.
A batch of coarse grained aggregate powders was investigated regarding its shape parameters.
“Coarse-Grained Refractory Composite Castables Based on Alumina and Niobium”.

That band result shows that a partial RE3+ is apt to the interstitial sites or grain boundary.
Since the crystal structure unchanged in the samples, the change in wave number can be related to a change in the tetrahedral and octahedral sites occupation of doped ions of different ratios.
Small number RE3+ ions can occupy octahedral sites, while most number RE3+ ions only located on the interstitial site or grain boundary [12].
Second are RE3+ ions into the interstitial site or grain boundary, filled the space between each ion and inhibited the grain growth by spin [17], which cause the density increase.
Because the ionic radius difference, the Mn3+ ions substitutes the B-sites Fe3+ enters into the octahedral sites, while the RE3+ ions are apt to diffuse to the grain boundaries and form an isolating ultra-thin layer around the grains.

As Si content was increased, the number and size of carbide decreased and full ferrite matrix were obtained.
Eutectic carbides were found at grain boundries in the Si 4.2wt% specimens and some black phases were also observed.
Carbides sized several to tens of μm existed inside the ferrite grain and decreased as the Si content increased.
As the temperature increased, the ferrite grains transform to austenite, but not all were transformed.
Instead, the number of graphite grains decreased and size increased except the Si 6.0wt% specimens.

In addition, the grain size and grain number of the silver wires were measured as shown in Fig. 2 and some unusual large equiaxed grains were found in the 275℃ annealed wire (see Fig. 2 (d), grain size 16~24mm).
In the HAZ area, coarse grains could be found.
Pure silver wires consisted of equiaxed grains, but the distribution of grain size was wide range.
Numerous fine grains were both found in AgLa375 wires and pure silver wire, indicated that they had more potential of grain growth.
FAB with 85μm diameter from 20μm pure silver wire was too huge to bond, and it consisted of a large number of columnar grains.

Over the years, the self-propagating high-temperature synthesis (SHS) has become an interesting research field to prepare a large numbers of advanced materials.
Several reviews, large numbers of papers and patents on various aspects of material production by SHS are available in literature.
The addition of C also found to decrease the grain size and fine grained ZrB2-C composite could be obtained with high densification.
It was observed that Ti/Zr containing grains were finer than Al containing grains.
For sample with no Ti diluent addition boride grains varied between 1 to 0.5 μm, whereas alumina grain varied between 1 to 4μm.

Semi-solid alloy grains can agglomerate, sinter and coalesce.
In some non-stirred annealed metal systems, grains in contact crystallographically align to minimize the grain boundary energy due to thermal forces alone [11].
The thermally separated arms and stems further ripen to globular grains.
This was considered sufficiently large for a statistical image analysis with negligible image boundary-effects, because the amount of globules/aggregates cut by the image boundary is a small percentage of the total analysed number.
They may be either a globular grain, or a side-branch of a more complex grain [10].

The results showed that the extruded TMCs had a duplex microstructure consisting of coarse alpha titanium grains and ultrafine grained (UFG) regions, and the in-situ formed TiC particles had a near-spherical shape.
However, in some other local areas, the matrix consisted of many ultrafine grains as shown in Fig. 5(d), and the grain size was around 200 nm.
From the morphologies of the fracture surfaces of the tensile test specimens shown in Fig. 8, it can be seen that the extruded Ti (Fig. 8(a)) exhibited a typical ductile fracture feature, as evidenced by a large number of small dimples existing on the fracture surfaces.
Dislocations are tangled and piled up around the in-situ TiC particles and the grain boundaries of the ultrafine grains, which make the stress concentration increase and lead to a higher strength.
Acknowledgement Funding from National Natural Science Foundation of China (Project Number: 51271115 ) and the Ministry of Science and Technology through a 973 project on the scientific basis of fabrication of advanced metal matrix composites (No.2012CB619600) in gratefully acknowledged.

The samples were austenitised at 1100°C for 30 min which resulted in an austenite grain size of about 60 mm.
The TEM study of the samples after thermomechanical processing showed the formation of interphase precipitate with the average size of 5.2±0.5 nm and number density of 5.15x10+7, (Fig. 1a).
The numbers of atoms analyzed for (a) is 940327.
A maximum enrichment of carbon at the grain boundary of 3±0.3 (at.%) was found (Fig. 4a).
Atom map showing the presence of carbon segregation at grain boundary (a) (G1 and G2 are grain 1 and grain 2 respectively), segregation of carbon across the phase boundary (b) and segregation of phosphorous across the phase boundary (c).

The grain boundary is relatively thick and non-equilibrium eutectic compounds net-like continuous distribution in grain boundary, a large number of globular second phase particles distribution in the dendrite and grain boundary.
As shown in figure 1c, we can see a large number of acicular and dot phase within the grain.
XRD analysis of different homogenization processing state (1-430°C /18h; 2-430°C /36h; 3-430°C /18h+467°C/4h) As shown in figure 6a, grain boundary is composed by a bulky residue eutectic alloy and dendrite network composition after 10 hour's homogenization treatment, large numbers of intermetallic compound can be seen inside the crystal.
As the duration of homogenization, non-equilibrium eutectic compounds on grain boundary began to disappear which is network-like distribution, the grain boundary become thinner and the second phase began to dissolve inside crystal(Fig 6).
After 18 hour's homogenization (Fig. 6c) the second phase on the grain boundary almost disappeared, and the grain boundary become obviously refined, second phase fully dissolved inside the crystal.

Also a number of precipitates were detected.
The texture strengthens with increasing number of rolling passes while still preserving the component in the transverse direction (hereafter called the TDcomponent).
The recrystallised grains are further divided into groups with grain sizes < 2 µm and > 2 µm.
The grains of the latter group are regarded as grains that experienced grain growth, in contrast to the small grains which are in an early stage of growth after nucleation.
Acknowledgment The authors appreciate the financial support of this study by the Deutsche Forschungsgemeinschaft (Grant Numbers KA 1053/10-1 and LE 1395/3-1) as part of the World Materials Network.