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For a particulate structure with particles of α-phase in a homogeneous distribution of β-phase, the contiguity of α-phase is given by the amount of α-α contacts and α-β contacts: αβαβαβαβ αααααααα αααααααα PLPL PL C ++++ ==== 2 2 (1) where PLαα is the number of α-α intersections and PLαβ is the number of α-β intersections.
CC presents the classical dendritic structure with coarse grains involved by eutectic phase, UR sample shows a very homogeneous and non-dendritic structure, with lower grain size, EMS sample shows fragmented structure with grain size similar to the UR condition.
Although the similar grain sizes of EMS and UR structures, the relationship between dimensions of primary particles and grains is higher in the UR samples than in the EMS ones, denoting lower number of primary particles within the grain in the UR.
A low misorientation among particles is expected, depending basically on the heat flow direction during solidification, facilitating the agglomeration in the semi-solid range, resulting in a higher number of particles within the grain.
The relationship primary particles/grain denotes the degree of interconnection of the primary particles in the structure: higher the relationship denotes a non-connected structures, one grain is one detached primary particle; lower the relationship denotes a very interconnected structure in which one grain contains several primary particles.

As shown in Fig. 3a, b, c, columnar grains and the proeutectoid ferrite precipitates mainly distribute in the weld center along the grain boundary.
The microstructure of the grain interior is composed of tiny ferrite and pearlite, and.
So the tensile samples were taken from near surface, 1/4 thickness and 1/2 thickness of the start welding position and they were numbered A1, B1, C1.
The same sampling method was used to take tensile samples from the end welding position, and they were numbered A2, B2 and C2.
Moreover, the size of the ferrite grain in these two locations is about 20~35 µm.

However, PF models demands a large number of computer resources, so it can only simulate a few dendrites in a smaller domain.
The eutectic structures finally form at grains boundaries and the interdendrite regions.
The number of the casting cells and the chill cells is 157,558 and 133,560, respectively and the total number of macro cells including sand mould cells is 2,073,600.
As shown in Fig.5, grain size is smaller and secondary dendrite arm space is also smaller as the cooling rate increases.
These can be understood due to the fact that the increase of the cooling rate will lead to the increase of the undercooling and the number of nuclei in one certain domain, which causes the grains refining.

Its development, prevention or strict control are central to a surprising number of industrial processes and products so research into it has been driven by commercial as well as academic demands.
Although the cube texture develops first during primary recrystallisation, it continues to increase in strength during subsequent grain growth as smaller and less favoured grains are consumed by growth of the larger cube grains.
It seems unlikely that an OG mechanism based on ‘special’ grain boundaries is sufficient to account for the cube texture for a number of reasons.
In order to understand this it must be recognised that although the cube nuclei are very effective, they are also few in number.
Since they are few in number, a sharp texture, therefore, necessitates a large final grain size as is invariably observed.

The individual grain orientation was measured by EBSD in a FEG-SEM.
A great number of needle-shaped δ phase distributed in the grain boundaries disappeared after solution treatment.
With the increasing of hot deformed temperature, the dynamic recrystallized grains become more uniform and the grain size increased.
The dynamic recrystallized grains are finer than the original ones.
Fig. 4 (c) shows the typical neck-structure of superalloys which there are many fine recrystallized grains around the big grains.

The average grain size D was determined by Mendelson intercept method [11], which is based on the SEM micrographs using D=1.56×C/(MN), where C is the random lines length on the micrograph, M is the magnification of the micrograph, N is the number of the grain boundaries intercepted by the lines.
Therefore, it is attributed to the increase number of grain boundaries caused by the decrease of ZnO grain size.
As a result, the ZnO grain size decreased.
Cerium mainly segregated at the grain boundaries.
CeO2 acted as an inhibitor of ZnO grain growth due to the decrease of average grain size with increasing CeO2 content.

An increasing number of papers were concerned with the important issue being the thermal stability of the SPD nanomaterials.
Horita Following the successful research activities in the field of nanostructured SPD-produced materials, a number of international subject-related workshops and symposia have been held after the conference.
In particular, the International Symposium on Ultrafine-Grained Materials moved its sessions on all aspects of science and technology of bulk ultrafine-grained materials produced by SPD techniques and other techniques.
Lowe (eds.): Ultrafine Grained Materials II (The Minerals, Metals and Materials Society, Warrendale, PA 2002)
Lowe (eds.): Ultrafine Grained Materials III (The Minerals, Metals and Materials Society, Warrendale, PA 2004)

Overall, the effect of fine Cr carbides on grain boundary mobility in the LC-Cr steel causes variations in recrystallisation kinetics, grain morphology and micro-textures.
With greater annealing times nuclei also form in grain interiors on deformation defects such as in-grain shear bands.
Similar to the annealing of WR Cr-alloyed LC steels [8], the significant numbers of relatively coarse cementite and alloy carbides aligned parallel to the RD (Fig. 2 and [6]) become nucleation sites during later stages of recrystallisation in both steels.
In both steels the boundary misorientation of recovered grains shows a slight increase in HAGBs compared to deformed grains after 3s (LC) and 16s (LC-Cr) annealing (Fig. 4).
While the g-fiber of nucleated grains in both steels are of similar strengths, the peaks of growing grains in LC-Cr steel are weaker and have a larger orientation spread.

Grain Boundary Faceting Phase Transition and Thermal Grooving in Cu B.B.
Grain 1 in this bicrystal is completely surrounded by grain 2.
The grain 1 in this bicrystal is completely surrounded by the grain 2 forming the Σ9 <110>tilt GB.
The <110> axes in both grains are parallel to the growth axis.
Westmacott and Dahmen observed that a small Al grain embedded in another Al grain had a polyhedral shape at low temperatures [26].

It was observed that more number of grains (~75%) lies between 40-60 µm sizes in case of LAT971C.
The high number fraction of lower grain size (<30 µm) is increased in case of LAT971R.
This confirms the presence of more number of strain free grains, which is attributed to the dynamic recrystallization (DRX) in α-phase as a result of homogenization and hot rolling at ~573K [12].
This was estimated by providing a criterion for the grain boundary (misorientation exceeding 15o) and then isolating the grains.
For a given grain, the average misorientation was calculated between all neighboring data points in the grain.