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However, the TFTs with single grain-like polycrystalline channel under the recent fabrication technology frequently demonstrate non-uniform electrical characteristics because of the grain boundary traps, bulk grain traps, interface states and some defects on channel region [4].
The location of grain traps and grain boundary traps has indeed and randomly disturbed the TFT performance.
Additionally, grain boundary traps also affects the electron mobility.
This phenomenon is that the amount of grains in polycrystalline structure permutes the inner-atom of each grain which generates some dislocation in structure.
According to the experimental results, we also found the moving carriers colliding with lattices could generate a number of traps, which deteriorated the carrier velocity.

In the study process factors namely feed rate, speed and coolant were analysed to understand the effect on the surface roughness, percentage (%) of thickness reduction, grain size and hardness of the Aluminium (Al) sheet metal after forming.
In the study it is observed that, the surface roughness, percentage of thickness reduction, grain size and hardness, all are interrelated to each other and hence, it is necessary to employ statistical methods to predict these parameter’s dependency [3].
The obtained experimental results surface roughness, % of thickness reduction, grain size and hardness are tabulated below (Table 1).
Table 2 Model summary statistics for surface roughens, % of thickness reduction, grain size and hardness of incremental forming Source Standard deviation Mean R2 Adj.
The optimum search is then driven by the minimum tool path, in order to reduce the number of trials.

The average grain size of the powders obtained after hydrothermal treatment at 160ºC for 9h was about 30nm with cubic structure.
A number of important physical, chemical, mechanical or mixed procedures have been proposed, among which the hydrothermal method has been found to be very promising for the preparation of well optimized and non-agglomerated powders [5-10].
The grain size of the powders was estimated using the Scherer's equation: θβλ cos/kd = (3) where d is the grain size, k sharp factor(0.9), λ the wave length of X-ray (0.15406nm), β the full width at half maximum(FWHM), and θ the Bragg angle.
average grain size was about 30nm with uniform distribution, which was in good agreement with the grain size determined from XRD.
Acknowledgements This work was partly financially supported by National Hi-Tech Research and Development Program of the People's Republic of China (Project Number: 2004AA32G090 ).

The results show that the specimens have uneven microstructure, and the grains are relatively small.
The grains grow mainly by the form of columnar and cluster-like, and there are obviously preferred orientation in the (220) plane.
Grain size: Considering the diffraction peak broadening caused by the grain size, the relationship between grain size D and the width of its real point β can be given by Scherrer formula: D (h k l) =k λ/β cos θ
Grain size of each small columnar is about 5μm.
Since the whole grain is in equilibrium, when the LIGA Ni micro-structure only exist micro-stress, the grain in a certain part is tensile stress, while the other part is the compressive stress.

The refinement of original grains was observed.
Number of passes are applied to the specimen resulting in a variation of crystallographic during the procedure by the strain accumulation [2-7].
Ferrite content was estimated terms of extended ferrite number (EFN) using Fischer ferrite scope.
There is significant reduction in the grain size.
The initial average grain size was 15.4 µm and after ECAP the grain size is 11.2 µm. 25µm 25µm a b Fig.3.

Both grain boundary energy and stored energy are taken into account in the calculations.
Moreover, relations for grain boundary energy and mobility have to be used.
The structure of grains is defined by a set of vertices (triple points) with positions rk where k=1,..., N (N is the number of vertices in a model sample).
Each (sub)grain has a homogeneous structure and is characterized by its orientation gi and SE value Ei.
Basing on experimental observations [9,10], it was proposed that a grain boundary can move only if the SE difference between two neighboring grains is higher than some critical value ∆E (called the SE threshold).

BaFe12O19 substituted sample shows a single semicircle at lower temperature and two overlapped arcs at 120 and 160 oC due to grain and grain boundary.
The electrical resistivity contribution by the bulk material (grain), grain boundaries or electrode can be identified from the arcs [3].
BaTiO3 phase was indexed based on the standard JCPDS data number 05-0626 for tetragonal structure.
R1 is much higher compared to R2 due to difficulty of the charges to move in the grain boundary compared to in the grain.
From 25 to 80 oC, the grain boundary relaxation peak frequency decreases with temperature but the Z“ value increases showing an increment in the grain boundary capacitance.

Results and Discussion Before ECAP the microstructure of the alloy had uniform equiaxed grains with the average size of about 9 µm.
It is seen that the ECAP route used gives rise to an ultrafine-grained structure of the alloy with the average grain size ~ 1-5 µm.
The observed changes in the texture are a consequence of the ECAP features and depend on the route of pressing chosen and the total number of passes.
At the same time, a pronounced microstructure refinement at the level of the grains and subgrains occurs.
This texture, in combination with the grain size refinement down to the average grain size of ~ 1-5 µm, is responsible for the observed improvement of ductility.

Finite element modelling can be used to enable the manufacturing of complex-shaped parts economically as the number of experimental trials can be reduced.
The finite element calculations take into account also grain size evolution.
This included two aspects as follows: Grain Growth.
(1) The static grain growth ̇dstatic in Eq. 2 captures the grain growth by atomic diffusion due to the high temperatures in the absence of deformation conditions.
Fig. 1 also shows that the grain size values of Ti64 alloy are higher than those of Ti54M alloy as the rate of grain growth of Ti64 alloy was higher than that of Ti54M alloy and the initial grain size of Ti64 alloy was greater than that of Ti54M alloy.

These lamellar LPSO phases arranged in the same direction in the same crystal grain, and arranged in different directions in different grains.
At the same time, it can be found that the number of particle phases decreased significantly, indicating that precipitated phases reintegrated into the matrix with the increase of deformation temperature.
A mass of DRX grains were produced after 1 pass.
After 2 passes, the grain size was consistent with the 1 pass.
A large number of precipitated phases produced with the decrease of the deformation temperature, which can pin the grain boundaries, so that the fine DRXed grains maintained the stability of the grain size during thermal deformation process.