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Fig. 4 showed the average grain size on function of repairs number.
It is clear grain growth with the number of repairs.
It is clear that average grain size increases with the number of repairs, which in turn decreases the hardness.
Average grain size and Vickers hardness relate to average residual stresses in function of repairs number.
In general, the grain size increases with the number of repairs, however not clear tendency with the number of repairs was observed.

Experimental studies performed on a number of superplastic materials and review of literature indicates sliding of grain groups suggesting a process of cooperative movement of grains.
Movement of grain boundary dislocations associated with a step at the core causes coupling of sliding and grain boundary migration, and cooperative manner of grain sliding leads to a long range correlation in grain boundary migration.
Introduction: Cooperative Deformation Processes It has been shown in a number of superplastic (SP) materials [1-10] that grain boundary sliding occurs in a cooperative manner, i.e. groups of grains slide as blocks.
Cooperated sliding of grain groups is accompanied by cooperative grain groups rotation (CGBR), i.e. rotation of grain groups, and cooperated grain boundary migration (CGBS), i.e. correlated migration of sliding grain boundaries.
Coupling between CGBS and grain boundary migration can be attributed to motion of grain boundary dislocations associated with a grain boundary step resulting in relative grain displacement and grain boundary migration [8].

Introduction The triple junction of grains is a linear defect, along which three variously oriented grains or three grain boundary surfaces are conjugated.
The grain boundaries are denoted by the bright dashed lines.
The grain boundaries are marked by thick gray lines.
As a result of rapid cooling, a large number of defects formed in the calculation block in addition to the grain boundaries: pores, vacancies, dislocations, disclinations.
The reason for the formation in polycrystals a large number of the strained triple junctions having a relatively "loose" structure with a high share of the free volume was elucidated in the study of crystallization in the three-dimensional molecular dynamics model.

The cavities at the triangle grain boundaries are present in V-shape, others near the second phase particles and within grains are present in O-shape.
The number, shape and distribution of cavitation after superplastic deformation greatly affect mechanical capability of parts.
Cavities on grain boundary join into each other.
But the strengthen phase CuAl2 and Al2CuMg of the original structure in tensile specimen has taken place big change in number, shape and size.
The numbers, sizes of cavity have apparently increased, and the superplasticity also is less than that of Fig.3 (a).

Introduction In the 1950s，cooling process of fermented grains was carried out by handwork airing.
But the production environment is not fundamentally improved, in addition, there were a number of problems, for example, ou went, and the ferment grain may be contaminated since it’s still stacked in environment of human activities in certain period.
The retort distilled grains are piled in the front of the lowest point of the airing on-field.
The barrels are hung by crane to pour the distilled grains into feeding-grains machine, and it will perform when everything is fine, start the airing machine while regulating the parameter in great condition until the distilled grains drop on the sheets.
Comparison of the uniformity of unfermented grains of the different airing ways.

Mechanical Spectroscopy of Ultrafine Grained Copper I.S.
Increased amplitude dependent damping in ultrafine-grained copper is believed to be associated with a dislocation mechanism, rather than a grain boundary mechanism.
In Fig. 3b the grain size is also indicated for several temperatures.
At ε0 > 2.5×10-4, the values of IF depend on the number of cycles, see the arrow pointing from the n1 to the n7 cycle in Fig. 7.
This contribution drops with an increase in the grain size.

In the low angle grain boundary with a tilt angle (2θ) of 2.1o consisted of the periodic dislocations array, the interval of those dislocations could be explained by the dislocation model for grain boundary.
Since the ultrafine grained materials have numerous number of the grain boundaries, it can be easily predicted that those mechanical properties must be governed by their grain boundaries.
The mean lamellar spacing of the grains elongated to RD is approximately 200nm.
In the ARB processed specimen, two types of grain boundaries are observed.
They called this a kind of non-equilibrium grain boundary.

Growth of individual austenite grains measured with 3DXRD microscopy V.I.
The chemical compositions of the studied alloys, in wt.%, are (numbers in brackets are for C35 alloy): 0.21(0.36) C; 0.513(0.65) Mn; 0.2(0.3) Si; 0.086(0.23) Cu; 0.021(0.177) Cr; 0.049(0.092) Ni; less than 0.01 Mo, Sn, P, S.
By slightly rotating the sample around an axis perpendicular to the beam over an angle of 0.5º, a number of grains give rise to diffraction spots on a 2D-detector.
Growth type two is attributed to the nucleation and growth of new grains on the F-F grain boundaries (see Fig. 2b).
It was shown earlier [5] that at the very early stages of the transformation the formation of austenite on the F-F grain boundaries (at quadruple points, grain edges and grain boundaries) can take place.

The effect of the number of pressings on the tensile ductility is considerable.
The following conclusions can be drawn: (1) a rather equiaxed uniform grain/cell structure tends to form regardless of the processing route when the number of passes exceeds 16, although at smaller number of passes the grain shape depends on processing rather strongly [2,10]; the AR value in A specimens is even slightly higher than that in the Bc specimens indicating intensive fragmentation of the pan-cake or fibrous structure, which is typically formed after ECAP by route A during first pressings
It is apparent that the increasing number of pressings gives rise to considerable reduction of the total heat effect upon annealing.
Similarly, the facture surface appeared virtually independent of the number of passes.
We also notice some trend towards increasing ductility with increasing number of passes from 16 to 20.

Higher microhardness numbers were generally found near the casting surface, at the corners and along the segregation band.
The majority of lower hardness numbers was found at the core region.
A few very low hardness number points, in the range 30~45 Hv, were also found in the core region.
Many of the highest hardness number concentrate at one of the corners in Fig. 1-a.
Dendritic grains appeared dispersed in the surface and corner regions as well, although they were much fewer in number than at the core.