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It is now recognized that processing by equal-channel angular pressing (ECAP) leads to very significant grain refinement in polycrystalline materials with the as-pressed grains typically having sizes within the submicrometer range.
However, despite the large numbers of experimental investigations of ECAP conducted to date, very little information is currently available on the mechanism of grain refinement.
Samples were annealed prior to pressing to give an initial grain size of ~1 mm.
For each map, the contour lines enclose areas having similar values of microhardness to within a value of 5 on the scale for Hv and the numbers on the lines represent the contours for specific values of Hv.
Ultimately, the appearance of the microstructure remains essentially unchanged with higher numbers of passes.

In order to accurately identify the grain insects, the system required a single-layer grain sample [8].
We only need to collect one image of the grain insects rather than more to complete the detection of one grain sample.
Stored-grain Insects Screening Device and Grain Samples Stored-grain Insects Screening Device.
The dead insects could not be sieve out from the sieve sometimes, and the total number of the insects sieved out successfully was less.
Detection techniques for stored-product insects in grain [J].

At high temperatures, grain fragmentation takes place due to frequent formation of kink bands initially at corrugated grain boundaries and then in grain interiors, followed by full development of new grains in high strain.
It has been discussed in detail in elsewhere [7-9] that further deformation to moderate strains leads to increase in the misorientaion angle and the number of kink bands.
Kink bands followed by new grains are scarcely developed in the twinned grain interiors.
When original grains are surrounded by fine grains, kink bands may be hardly developed in the remained original grains, because constrained deformation by surrounding grains can be relaxed by operation of grain boundary sliding and dynamic recovery in the surrounding fine grained region.
The misorientation and the number of boundaries of kink band rapidly increase with deformation, finally followed by the evolution in-situ of new grains with high angle boundaries in high strain

Results and Discussions Fig. 1 shows the microstructures of ECAPed Al-3mass%Mg alloy with the number of passes.
The specimen of before ECAP processed had equiaxed grain structure, grain size of it was 134 μm.
Fig. 1 The microstructure of ECAPed Al-3mass%Mg alloy (a) before (b) 1 pass (c) 2 passes (d) 3 passes (e) 4 passes Fig. 2 shows variation of Vickers hardness and mean grain size with number of passes for ECAPed Al-3mass%Mg alloy.
The grain size decreased with increasing number of passes and maintained constant after 2 passes.
Fig. 2 Variation of Vickers hardness and mean grain size with number of passes for ECAPed Al-3mass%Mg alloy Fig. 3 shows the microstructures of ECAPed 4 passes Al-Mg alloy.

Structure and grain size.
The distribution of coincident site lattice in the samples indicates that after primary recrystallization, the largest number is ∑3 boundaries, and the second largest number is ∑13 or ∑11 boundaries.
Distribution of grain orientation.
For high permeability grain-oriented silicon steel by inherent inhibitor method, the best primary grain size is 10～15μm due to the inhibition, and secondary recrystallization would accomplish sufficiently with excellent magnetic properties [5].While for high permeability grain-oriented silicon steel by acquired inhibitor method, （Al,Si）N has to be formed by nitrogen injection before the final annealing to insure the enough numbers of inhibitor, so the primary grain size should be 18～30μm for ideal secondary recrystallization texture [6].
Harase J and Shimizu proposed that there are large numbers of CSL boundary around the growing Goss grains.

Therefore a number of literatures are found which report the beneficial utilisation of the orientation [10,13].
Average grain sizes were calculated by counting the number of crystal grains in these micrographs.
With the initial grain size of 18 and 26μm, huge grain structures were obtained at any reduction.
Initial grain sizes; 37μm.
During the grain growth, the grain boundary migrated at the expense of the strain.

Grain Boundary Relaxation in a Fe-Cr-Al Alloy Z.
Grain boundary relaxation strength remarkably decreases with increasing grain size.
When grain size reaches 520μm, the grain boundary relaxation peak almost disappears.
Large numbers of observations of grain boundary damping in internal friction experiments have been reported since the identification of Kê phenomenon [1-4].
Besides, the dependence of grain boundary relaxation on grain size has little been reported in Fe-Cr-X alloys.

In the present study, controlling conditions in hot rolling such as temperature, total number of passes, reduction in a pass, etc. have been investigated in a Zn-Al eutectoid alloy to obtain fine-grained microstructures.
Therefore, in the present study, control conditions in hot rolling such as temperature, total number of passes, reduction in a pass, etc. have been investigated in a Zn-Al eutectoid alloy to obtain fine-grained microstructures.
Degree of grain refinement was assessed with average grain size.
The average grain size tends to increase as the process proceeds (with increasing number of pass) within the range from 1.4 to 1.9mm.
Number of passes, N 1.2 1.4 1.6 1.8 2 5 6 7 8 9 10 Average grain size, L/mm Fig. 3 Effect of number of passes on average grain size References [1] Y.

The grinding coefficient of cutting discs with tangential orientation of abrasive grains is 25-29% higher, than at usual discs with non-oriented grains.
The specified methods of production of abrasive tools possess a number of shortcomings.
Methodology for evaluating of the exploitation characterizations of the cutting discs It is known that the number of important operating characteristics of cutting discs include cutting ability (grinding productivity), wear (expense), effective power of cutting, surface quality of cut workpieces, their hardness and texture, maximal work speed, etc.
Radially oriented abrasive grains have sharper front angles in comparison with tangentially oriented grains.
Effective power of cutting discs with tangentially oriented abrasive grains is 4,8-4,9% lower, than at usual discs with non-oriented grains.

If grain size is 1µm and dislocation density is -2 12 -2 1 m (10 m ) µ , the number of dislocation lines contained in a grain is approximately one.
When the number of dislocation lines contained in a grain is sufficiently small in the initial state, slip deformation of a crystal hardly occurs and critical resolved shear stress increases.
While, the number of dislocation lines contained in a fine-grain changes depending on grain size, even if the dislocation densities are the same value.
Assuming the number of dislocation lines, which is necessary to start slip deformation as a usual metal, to be constant regardless of grain size, the value of ( ) k α ρ increases with decrease of grain size.
Yield behavior of fine-grained metals depends on the initial grain size and the initial dislocation density.