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The proportion of twinned grains increases with the increased strain rates.
The number of independent slip system in TiAl is less than five independent slip system[2, 3].
In TiAl, as the strain rate increases, resistance to dislocation motion increases and the grains tend to twin [14].
(4) The plastic deformation easily occurs in equaxied grains of DP TiAl.
Kim, Mechanical Behavior of a Fine-Grained Duplex Gamma-TiAl Alloy.

Due to rolling, the grains were deformed.
With increased Sn concentration, grain size decreases, and the number of precipitated particles increases.
Some smaller grains are among the deformed grains, indicating recrystallization during hot rolling.
It has also been found that increasing Sn concentration increases the number of intermetallic particles [7].
When the alloy's Sn concentration is raised to 2%, the particles spread homogenously across most of the grain, leaving only some grains unoccupied (Fig. 4(e)).

Different passes deformation samples will be numbered, then the data for the experiment can be obtained by averaging values.
After the fourth deformation, the size of precipitation strengthening phase is about 4 μm and its number is increasing continuously, and at the same time, it is more and more disperse(Fig. 4(d)).
There is substructure in grains and in the process of deformation dynamic recovery occurs and grains enlarge obviously, as the strength decreases after the fifth deformation.
Because coarse precipitates distribute in the grains boundary, and during the fourth deformation, with the deformation pass increases, it is more and more dispersible along the grains boundary as a result of decreasing the strength of the grains boundary and expanding the tendency of the cracks along the grains boundary.
The grain and second phase becomes dispersible and well-distributed.

The coercivity showed a decrease at a grain size below 100 nm.
In this processing route, the cube element reserves to the original shape after an even number of passes.
This effect is also used for grain refinement in some SPD processes.
The susceptibility of the materials for magnetic hardening via ECAP is stronger for FeCo17, than for ARMCO® iron, especially for a low number of ECAP passes
Zhu, Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation.

Table 2: Mechanical Properties of Untreated and Annealing Condition Grain Size (ASTM) Hardness (HBW) Tensile Strength (MPa) Yield Strength (MPa) Elongation (% 50mm GL) Un Treated 7.0 269 786 646 17.32% Annealing 8.5 201 708 491 23.00% There was an increase in the observed grain size in the annealed samples, whose ASTM grain size number was measured to be 8.5, when compared with the untreated samples which had a grain size number of 7.
The grain size growth might be attributed to the alignment of atoms at the grain boundaries due to acquired thermal energy supplied during the annealing process.
The decrease in the Brinell hardness is attributed to the increase in the grain size and decrease in the strength due to reduction in grain boundary strengthening.
The changes in the tensile properties were also attributed to the change in the grain boundary strengthening phenomenon that depends upon the grain size.
The reduction in the yield and ultimate tensile strengths, and increase in the percentage elongation of the annealed specimens were also attributed to the increase in the grain size and reduction in the grain boundary, which reduces the strength of the material.

Although there are a large number of laws available, the most advanced physically-based models recently developed by the scientific community, which make use of more extensive information, are not commonly used in combination with the finite element method due to their complexity.
Single grain.
Starting with a first approximation (equal stress in every grain), grain strain rates are calculated with (2), and macroscopic magnitudes are found with (3).
Due to the simplifications possible when only one shape is considered for all the grains [12] and the small differences observed experimentally, all the grains are supposed to have the same ellipsoidal shape.
VPSC gives particularly good results, which is partly explained by the much larger number of parameters used.

The corrosion grooves at the grain boundaries surrounded all grains, that is, an obvious tendency for intergranular corrosion of materials was presented.
Obvious carbide corrosion grooves could also be traced in grains.
When such carbide grooves in grains were still small after the stabilizing heat treatment, nearly all carbides had gathered at the grain boundaries.
Coarse Grained Region Unmixed Zone Fig.10 The distribution of heat-affected zones in welding.
As the heating did not last enough, a large number of unmelted carbides, in the second phase, existed in the grains of remelted austenite and were densely distributed.

The added second metal oxide usually segregates at the grain boundary of the main oxide with a gradient concentration, or precipitates as cluster-sized particles either inside or on the surface of the grains.
It is known that the grain growth is one of the reasons of the gas sensor parameters instability during their exploitation [9].
Examples of additive influence on the grain size stability during thermal annealing are shown in Table 1.
Effects of additives and annealing temperature on TiO2 grain growth.
When MeI is a transition element (d-element), these reactions can change the MeII oxidation state, coordination number, and cation distribution between the surface and lattice positions.

Thus, there is no great difference in the grain sizes and their spread, which means that some other factors but not grain boundaries cause different values of the residual resistance.
However, at an enhanced oxygen content the large number of fine precipitates are formed, which, on the contrary, can cause the residual resistance growth.
Grain sizes in the stabilizing Cu are 20-250 µm, i.e. the grain size scatter is much wider than in pure copper.
Some grains grow across the whole sheath.
As the stabilizing copper grain sizes are close to the width of the sheath, the fraction of grain boundaries is very small, and only the volume diffusion of Cr was taken into account.

Each grain has a specific magnetic orientation, different from the other grains, so the alloy has a random texture.
Also, the hysteresis energy losses are strongly influenced by the number of impurities, which contribute to fine precipitates MnS and AlN formation.
These pinning sites inhibit the grain growth and have as result a grain diameter smaller than the mathematical optimum of 150 µm [17].
By reducing the number on impurities, it is hindered the chemical formation of MnS, AlN and carbonitride precipitates, which inhibit the grains’ growth and has a negative effect on the texture.
In high quality steels the number of impurities is very low and the excess (anomalous) energy losses are very reduced.