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Relevant data are available in a relatively large number on Al-Mg-Sc/Zr alloys with a Mg content ranging from 1 up to 6 mass % [8-12].
By increasing the number of passes, the sub-boundary misalignment increased, as confirmed by the increased spreading of the spots of the SAD patterns.
Grain structure of the materials investigated after 4 ECAP passes.
This effect is confirmed here by the shift of the above mentioned peaks toward lower temperatures by increasing the number of ECAP passes of the samples
Ultrafine grained materials.

The grain subdivision occurs with the appearance of many low angle grain boundaries.
The Miller indices are not perfectly orthogonal between ED and ND because the nearest integral numbers are used for them.
From the result of pole figure and the ODFs, one can see that the texture varies significantly with the number of ECAE passes.
The grain subdivision occurs with the appearance of many low angle grain boundaries. 2.
Ultrafine-grained materials III.

The grain sizes of the alloy were in the range of 150-250 µm.
After 1-pass ECAE, the interdendritic I phases were slightly broken, and a number of twins were observed within the original grains.
However, deformation structures were generally inhomogeneous and large grains with grain size above 10 µm were still present up to 4 passes.
Many dislocations were visible in the grains with some grain boundaries ill-defined.
The variation of the tensile behavior of the alloy with the number of ECAE passes may be due to the different grain size and texture formed during ECAE.

Presence of coincident site lattices (CSL) on grains boundaries was investigated by repere diffraction method [1].
Intensity of grains orientations grows with ТFR Fig.5.
The following aspects: increase of grains number with cubic and octahedron orientations at controlled rolling; macrosymmetry (axis 4) of areas with higher pole density; as well as azimuthal distribution of zone pole density - testify dynamic recrystallization (DR) of steels in this area.
Significant number of special boundaries has been revealed here by repere diffraction method, which are characterized by presence of coincidence site lattice (CSL), for instance, tetragonal CSL (Fig. 9).
Grain maximums {111} accompanying them in this temperature range contribute to properties of low-alloy steel as well [4-5].

The precipitate coarsening creates precipitate free zones (PFZs) near the material’s grain boundary that causes a difference in corrosion potentials between the grain boundary and the body of the grain [1].
However, there have been examples where IGC has progressed along an angled grain boundary, then continued along another longitudinal grain boundary [5-6].
Due to it being an extrusion, the grain structure is highly directional with very thin, pancake shaped grains.
Corrosion Path Generation Model: In this stage a number of simulated corrosions paths are created using a model based on the Monte Carlo method. 2.
This model was run and analyzed a number of times with different input conditions (for corrosion length and probability of turning) to test the effect of IGC length and vertical path deviation on the resulting stress concentration.

To satisfy this condition, the operation of at least 5 independent slip systems in each grain is necessary or having a sufficiently large number of grain boundaries, allowing various shifts and rotations that take place, e.g., during the superplastic flow, is necessary [7].
Doing so we take into account that the size of sub-grains is much smaller than that of grains.
We replace the sum of cosines of angles by the product of the number of boundaries (the upper limits of the sums) and the cosine of the average angle.
Then the number of boundaries is defined as М g = L/ dg and M f = L/ df, where dg and df are the average size of grains and low-angle fragments, respectively.
Size of low-angle fragments and grains.

Grain refinement by inoculation with chemical grain refiners is an important and effective approach for mitigating such problems [1].
The search for new and effective grain refiners and methods for grain refinement still continues.
The discussion will be focused on the mechanisms of grain refinement. 2.
Such oxides may act as substrates for nucleation but are not effective for grain refinement due to their poor wetability and low number density.
All these factors contribute to the grain refinement. 5.

To gain a more detailed insight into the influence of ECAP, we investigated the corrosion behavior of Al-Mg alloy with increasing the number of ECAP passes and compared them with their coarse grained counterparts.
The number of ECAP passes is 2 and 4, respectively.
With multipass ECAP, remarkable grain refinement occurs by repeated shear deformation, and the grains were refined to submicron level after four passes.
Meanwhile, high dislocation density within the grains can be observed.
Conclusions Corrosion resistance of Al-2.8%Mg alloy subjected to different number of ECAP passes were studied; and the results are summarized as follows

These structures show the penetration of the Goss grain into the grain boundary between the two neighboring grains.
The percentage of low angle grain boundaries between the Goss and the island grains is much higher than that between the Goss and the neighboring grains, indicating that the grains having a low angle grain boundary with the Goss grain tend to be trapped as island grains.
The low mobility grain boundary cannot keep abreast with other fast migrating grain boundaries of the Goss grain.
If the island grains form by solid-state wetting, Goss grains appear to grow dominantly by solid-state wetting since the number of island grains is so large.
Type I refers to the penetrated grain boundary formed by the two neighboring grains and the type II refers to the two grain boundaries formed by the penetrating Goss grain and two neighboring grains.

Inside grains a very low number density of TiN and AlN particles was observed.
Microstructure consisted of small equiaxed recrystallized grains and non-recrystallized grains (angle misorientation inside these grains was greater than 2°).
Fig. 4a shows that the number of grains in the matrix with the orientation close to the Goss texture (≤ 15°) was low.
Fig. 4 Microtexture of samples after the slow heating to the 620°C, supplier A: a. grains close to the Goss orientation + high angle boundaries (θ > 15°), b. the legend for Fig. 4a In the sheets after the slow heating to the 620°C the number density of precipitates was less than that in the sheets after the DCA.
However, the number density of precipitates in the sheets during the slow heating up to 620 °C decreased.