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Finally, it was found that the grain size and the mechanical connection between grains play an important role in determining the electronic and magnetic properties.
By this result, it is expected that the grain size and the mechanical connection between grains play an important role in the electronic conduction.
Therefore, the lower energy shifts in Fig. 4 indcate that the valence number of Mn decreases.
The increase of grain size leads to the reduction of grain boundary.
Acknowledgement This work was supported by the KOSEF through q-Psi and Grant Number 04-2002-000-00009-0 and by Korea Research Foundation Grants (KRF-2001-015-DP0193 and KRF-2001-015-DS0015).

With rising annealing time, the number of low angle boundary (0～15o) decreased due to the mergence of grain with sub-boundary.
It can been seen that the average grain size increased with rising annealing time The abnormal growth of partial grains resulted in the increase of average grain size.
Large number of boundaries fell into the range of more than 15° in misorientation angles in all IF steels.
The number of low angle boundary (0～15°) increased and that of high angle boundary decreased (45～65o) with extending annealing time.
With rising annealing time, the number of low angle boundary (0～15o) decreased due to the mergence of grain with sub-boundary.

The Effect of Copper Content on the Dynamic Grain Growth in AL-Cu-Zr systems K.
An increase in grain size occurred in both materials due to deformation, but this dynamic grain growth (DGG) was much greater in the material with the higher copper content.
An increase in grain size with strain - dynamic grain growth - during hot deformation is a common characteristic reported for a number of materials, and is characterised by a grain growth rate significantly exceeding that which occurs in the absence of plastic strain [5].
This shows that both alloys have undergone dynamic grain growth.
With 2wt% Cu, the initial banded grain structure persisted to large strains and there was relatively little dynamic grain growth.

The surface layer of the hardness indentations was removed by acid solution to observe microstructure beneath the indentations, where a large number of bending, delamination and kinking grains were found.
It is worth noting that a number of buckling grains can be observed.
The formation of numerous cavities or voids resulted from the deformation of Ti3SiC2 because it possesses small number of independent slip systems.
A number of dislocations and stacking faults can be observed in the basal planes under TEM.
A large number of basal plane dislocations and planar defects exist in grains and at grain boundaries.

It is therefore necessary to evaluate the Schmid value, m of all potential slip systems in order determine the actual number of active slip systems.
As a consequence, it is very difficult to determine the number of activated slip systems in grains with this or similar orientations.
It is clear that the slip behaviour depends upon the initial crystallographic orientation, i.e. the number slip systems activated is very heterogeneous through the profile thickness.
Fig. 6: Rotation path of the tensile direction during increasing deformation. a) Grain A. b) Grain B c) Grain C d) Grain D and e) Grain E.
• The number of slip systems activated during deformation is strongly dependent upon the initial orientation and is therefore very heterogeneous through the microstructure

Introduction Ultrafine grained steels and alloys with a grain size below one micron are considered as advanced structural materials, which exhibit superior mechanical properties [1].
The longitudinal grain boundaries among ferrite lamellas are characterised by a wide variety of their angular misorientations from low-angle subboundaries to high-angle grain boundaries.
The numbers indicate the boundary misorientations in degrees.
The grain refinement during the cold rolling is accompanied by a drastic increase in the dislocation density in grain/subgrain interiors.
This annealed microstructure looks like the cold rolled one consisting of highly elongated austenite/ferrite grains with an almost random grain boundary misorientation distribution and high dislocation density in grain/subgrain interiors.

Introduction Recently, ultrafine grained (UFG) materials with grain size less than 1-m have been studied extensively, since they are expected to provide high strength without the degradation of toughness.
Although the authors do not have physical insight at the moment, it is expected that the small grain size including subgrain width would inhibit the formation of dislocation cells within grains.
Fig.5 TEM micrograph of 5083 Al alloy, cryo-rolled with 85% reduction and annealed at 250 � for 1 hr showing : (a) the presence recrystallized grains of 1.5 ~ 2µm in a diameter and non-recrystallized grains; and (b) elongated and equiaxed grains in non-recrystallized regions of (a).
Fig. 5 shows the duplex microstructure consisting of recrystallized grains and non-recrystallized grains in samples annealed at 250 � , as observed by Morris, et al [8].
The presence of equiaxed grains can be observed even in non-recrystallized regions, Fig. 5-b.

The driving force for boundary motion was provided by the surface tension of a curved grain boundary: bp a= γ , where bγ is the grain boundary surface tension and a is the width of the shrinking grain [10].
Similar to the 8.4° <100> grain boundary, a 12.0°<100> grain boundary (bicrystal B) did not move in a conventional way.
Behavior of a 14.3° <100> grain boundary (bicrystal C) at 580°C.
Behavior of a 14.3° <100> grain boundary (bicrystal C) at 600°C.
The change of the shape of this boundary above 510°C can be understood as a roughening of the low energy symmetric grain boundary configuration, as observed and discussed in a number of studies on special high angle CSL grain boundaries [3,7,8].

It was found that as the number of deformation passes increased, the coarse grains decreased, and the dynamic recrystallization fraction increased.
As shown in Fig. 2(a), after one pass of deformation, the microstructure still retained large number of coarse grains containing densely distributed lamellar LPSO phases.
Large number of low angle grain boundaries distributed inside, and the original grain boundary was jagged, surrounded by a large number of small DRX grains, showing random colors, indicating that the DRX grains had random orientation.
As the number of deformation passes increased, the DRX range increased, and the DRX grains became smaller.
In combination with Fig. 7, it can be found that the area with high KAM value usually had large number of low angle grain boundaries, which indicates that large number of dislocations accumulated in this area.

However phosphorus is easy to segregate at grain boundary and lead to cold work embrittlement[5-6].
Among grain boundaries, the coincidence site lattice(CSL) grain boundaries and misorientation between grain are known have a significant role in the recrystallization and the grain growth process and the segregation of impurity elements at grain boundaries.
The polygonal ferrites are obtained and the average grain diameters are 6~8μm.
It is evident that most of the grains are <111>//ND orientation texture.
And only small numbers of grains are <100>//ND and <110>//ND orientation texture. 50μm 50μm (a)0.035%P (b)0.056%P 50μm (c)0.079%P (d)IPF Fig.1.