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This suggests the occurrence of grain boundary sliding, probably with the help of tiny recrystallized grains existed in the vicinity around grain boundaries.
However, the macroscopic deformation must be impossible to occur just by the grain boundary sliding, because of the large grain size of the plate-like LPSO-phases.
The annealing of specimen at 400 ˚C for 168 h effectively coarsened the tiny recrystallized grains in the vicinity of the grain boundaries as shown in Fig. 3.
In this evaluation, the average length of long-axis of plate-like LPSO-phase grains was estimated as a grain size d.
The equation indicates that the decrease of orientation factor (Taylor factor) m reduces the k-value, which is brought about by the increase of the number of slip systems [7].

The minimum grain size was considered to be 27 voxels.
Angle θ displays the orientation of the long axis of the grain with respect to the RD and (d) quantification of the number of grains with long axes oriented at different angle with respect to the sample RD.
The grain shape of each individual grain was approximated with an ellipsoid (Fig.4a).
After applying both cleaning methods, the total number of grains remaining from the scan was 215.
RD and TD oriented grains).

As the creep mechanism, all tests show grain boundary diffusion or Coble creep is the dominate deformation mechanism, except at higher temperature 750 ºC and higher stress levels.
Under this circumstance, creep failure is diffused by grain boundaries and the minimum creep rate is determined by the following equation [3-7]: (2) where K is a constant (μm-4/mol), Dgb is the grain boundary self-diffusion coefficient (μm3/s), δ is the width of grain boundary (μm), Ω is the atomic volume (μm3), s is the applied stress (N/μm2), d is the grain size (μm), R = 8.314 J/mol K, and T is the testing temperature (K).
Measured grain sizes of 409L and 436 are 18 and 14 μm, respectively; the width of grain boundary is 3 μm for both stainless steels.
Grain boundary diffusional mechanism is the main creep deformation mechanism at 600ºC and at the lower stress levels of 750ºC. 3.
Acknowledgements This work was supported by the Industrial Technology Development Program, Ministry of Economic Affairs of Taiwan under grant number 100-EC-17-A-16-I1-0025 to Yieh United Steel Corporation (YUSCO).

There tends to be a higher density of dispersoids near the grain boundaries than in the centre of the grains, and this non-uniformity is found to be due to the presence of the cored dendritic structure after casting[4, 6], as there is not enough time to level out the microsegregations through diffusion before nucleation begins.
After grinding, the samples were polished with a fabric with diamond spray with grain sizes down to 1 µm.
These were taken in a straight line through the alloys, covering a distance of 1500 µm, crossing approximately 18-22 grains.
Results Number Density and % Area.
Fig.2 shows results for the number density and % area of both alloys.

It is thermodynamically preferred because, with grain size increased, the total surface energy decreases due to the smaller specific area of the grain boundary.
The grain size of the anatase observed as around 20 to 30 nm is comparable to data presented in Table 1 while the grain sizes of the rutile phase does not match well.
In spite of the small number of observations to be statistically meaningful, the gap between the calculation and the observation is 133% which could be regarded high.
The pores observed were significantly disappeared with the development of the larger grains of the rutile phase which resulted in the less grain boundary to form pores.
Nonetheless, fiber diameters were not observed to be decreased drastically probably because the number of observations was not many enough to be statistically meaningful to exhibit the differences in the porosity and the density.

The solid grains coarsened as deformation temperature increased.
When the number of neurons in each hidden layer exceeds 3, RMSE drops sharply.
As a whole, RMSE decreases with the increase of the number of neurons and the number of hidden layers.
While more hidden layers and number of neurons could reduce computational efficiency.
These deformed grains show preferential orientation.

The effects of stochastic distribution of grain nuclei, grain size and grain morphology are carried out for the validity of the simulated microstructure.
According to metallurgy, the growth of grain is from the grain nucleus in all the directions at the same speed until it encounters with others grains.
Each grain is assumed to be orthotropic and the orientation of the principal material directions differs from grain to grain.
In fact, these grain orientations for the grains composed of the microstructure are generated by a random number generating routine.
As described above, the grain orientations can be generated with a random number generating routine.

However, at larger number of revolution the deformation progressively reaches the sample centre and the final material exhibits an ultrafine grained composite structure.
Pure metals or commercial alloys processed by SPD typically exhibit a grain size in a range 100 to 500 nm.
However, it has been demonstrated that composite materials (for instance multi-phase metallic alloys) processed by SPD may exhibit a much smaller grain size down to 20nm [3, 4, 5, 6].
Thus interphase boundaries play a critical role in the grain size reduction mechanism.
For higher number of revolutions by HPT, the deformation progressively reaches the sample center and the original lamellar structure completely disappear (Fig. 3 and Fig. 4)).

We can see that its microhardness numbers, ultimate stress and tensile strain-to-fracture value grow with the degree of deformation (Fig.2) or a number of multigrains generated in the SPD processed SHS intermetallic compound.
The figures stand for grain and interlayer size, respectively.
The microhardness numbers of SHS intermetallic compound Ni3Al as depended on the SHS process type.
The effect of grain size on the yield strength of Ni3Al//Acta Met. -1985.
Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation.-2006.

Nucleation of eutectic cells is modelled using an Oldfield-type nucleation model where the number of nuclei in the melt is determined by the amount of active nuclei and the local undercooling from the surface to the centre of a plate casting.
Eutectic grains are modelled as spheres growing between the dendrites.
The number of eutectic cells per m3 formed in each time step is calculated in each element using Eq. 3.
Taylor, Three-dimensional analysis of eutectic grains in hypoeutectic Al-Si alloys, Mat.
Dahle, Aluminium phosphide as a eutectic grain nucleus in hypoeutectic AI-Si alloys, J.