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With the increase of the pressure, the number of the voids in the materials decreased, the density and the hardness increased, the change of the grain size was not obvious.
As shown in Fig. 3, there were coarse grain zones and fine grain areas after hot pressing.
After thermal deformation, the grain grown in orientation, the width of the grains decreased and the grains changed to flat morphology.
When height reduction was low, the grain orientation was not obvious.
The equiaxed grains were oriented in the direction of the pressure direction after deformation.

The creep mechanism of the composite is dislocation and grain boundary sliding control.
The current study results of magnesium alloy creep show that their creep deformation mechanism is dislocation slip mode and grain boundary sliding mode[9].
The non-continuous precipitation organizations make the movement and slip of the grain boundary be able to be carried out easily; while the movement and slip of the grain boundary carry through the form of dislocations, the creep fracture surface of the specimen must have obvious steps.
At a high temperature, plastic deformation of the matrix should be evident, that is, there exists a large number of dimples; and the fracture surface with clear micro-cracks.
In the preparation process of the composite material, because of a small number of poor bonding interfaces between the fibers and matrix, there are flaws and micro-cracks.

Compared with the low-nitrogen steel, the number of precipitates in decreased significantly and the size increased obviously in the high-nitrogen steel.
Besides, a small amount of 90~260nm irregular particles distribute on the grain boundary.
Nearby the high energy grain boundary, the dislocation density is high.
The number of precipitates was obviously decreased, and the size of which was larger than that of low-nitrogen steels.
Ultra-fine Grained Steel-Theories and Technologies of Structure Fined[M].

The flat grain boundary (Fig. 2 a) included, for example, the grain boundaries in which {100}<011> grain was adjacent to {111}<112> grain.
Grain boundaries with fine grains (Fig. 2 c) comprised the various combinations of differently oriented neighboring grains as shown in Table 1; expressly, grains of {111}<011> and {111}<112>.
With a focus on the fine grains in the grain boundary (type 3), an attempt was made to statistically examine the relationship between the characteristics of the grain boundary and the formation of fine grains.
It was found that in the examination of the 84 grain boundaries, 22 grain boundaries formed fine grains.
The number of grain boundaries with fine grains, in particular having ND//<111>, is counted. g1, g2, a1, and a2 stand for orientation of {111}<112>, {111}<011>, {100}<011> , and {211}<011>, respectively [11].

Heavy deformation was introduced in the samples after a considerable number of ECAP passes, from 1 to 16.
The number of ECAP passes, namely 1, 4, 8, 12 and 16 promotes a significant grain refinement observed by transmission electron microscopy (TEM).
Fig. 2 Longitudinal wave velocity vs. the number of ECAP passes for nanostructured copper.
Fig. 3 Transversal wave velocity vs. the number of ECAP passes for nanostructured copper.
A bimodal grain size distribution developed for higher number of passes.

Dependence of the density of samples from fine-grained concrete on the amount of calcium stearate 3.5.
Dependence of the strength of samples from fine-grained concrete on the amount of calcium stearate 4.
By creating a hydrophobic film around the pore space, firstly, it reduces the permeability of large pores, and secondly, it reduces the number of pores with a size of 10-100 microns.
It increases the workability of the mortar mixture, reduces the size and number of pores, and therefore slows down water absorption, practically does not affect the strength characteristics.
Study of the kinetics of water absorption of fine-grained concrete.

Grain Boundary Velocities, v.
Sub-grain Boundary Growth.
The sub-grain mobilities were estimated from the average growth rates of large numbers of sub-grains during more standard annealing experiments outside the SEM.
Grain boundary velocities and mobilities.
ii) Sub-grain mobilities in the same alloys measured during sub-grain growth using a FEG-SEM gave mobilities one or two orders of magnitude lower than the grain boundaries but, quite surprisingly, mobilities close to those of a similar Al-Si alloy.

The ultimate tensile strength increases with the number of CGP passes from 767 (solution annealed) to 1162 MPa (after 2 cycles), similarly, yield strength increases from 269 (as received) to 328 MPa (after 2 cycles).
Some researchers have successfully processed low carbon steels [17-19] via CGP for obtaining fine grained structured materials.
This graphs reflect the increase in hardness number with the increasing the number of CGP cycle.
Langdon,The process of grain refinement in equal-channel angular pressing, 46(9), (1998), Acta Mater., 3317-3331
Park, Constrained groove pressing and its application to grain refinement of aluminum, 328, (2002), Mater.

In this paper we present the object oriented finite element analysis of a real microstructure in order to obtain displacement and the deformation of grains and grain boundaries.
Sample with indication of the area for diamond pyramid hardness tests, where the micrographs were obtained One approach for investigating the microstructural behavior is to reduce the representation of microstructures at a small number of physical parameters, like grain dimension or porosity, and to develop a model depending of these.
Example of ferritic grain 50μm 50μm Example of pearlitic grain a) b) Fig. 2.
The boundary of the grain after automated selection Fig. 5.
The boundary of the grain after manual selection Fig. 3.

Plate-like grain microstructures formed on the bottom part of the pellet, and vicinity of the surface was dense.
The plate-like grain was oriented in the ab-plane direction.
A number of studies have investigated the preparation of In2O3(ZnO)m as new transparent conducting electrodes for use in a variety of electronics devices, and the synthesis of a highly electrical conductive compound In2O3(ZnO)3 in a solid state reaction at low reaction temperature is required.
In the present study, since the ab-plane direction of the In2O3(ZnO)3 grain has high electrical conductivity, the plate-like grain was grown selectively.
In addition, for the silica substrate the plate-like grain was deposited by microwave heating.