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A large number of dislocations appeared when warm deformation was introduced and the size of the intragranular precipitates changed differently when the deformation was changed from 10% to 30%.
The dislocations tangle with each other in the intragranular and piled up around the grain boundary.
When the density of dislocations was low, trapping of vacancies would be reduced and the rest cannot offer enough nucleation and transformation positions leading to a decrease of the number of GP-zones and a coarsening of individual precipitates.
When the density of dislocations was high, it would not only restrain the formation of GP-zones, but also lead to an increased formation of equilibrium phase η transformed from η’ phase, which also decrease the number of η’ phase.
TEM micrographs of grain boundary precipitates of SPT6, SPD2T6 and SPD3T6 samples are shown in Fig.7.

Crystal clusters in the overheated zone were dominated by secondary α phase (dark-colored) (Fig. 2a2 and Fig. 2b2), and a large number of microcracks were generated at the grain boundaries (Fig. 2c2).
A large number of primary α equiaxial grains were distributed near the overheated zone, and the grain size was about 210±10 μm (Fig. 4a2-4a4 and Fig. 4b2).
Differently, a large number of secondary α equiaxial grains were distributed near the heat-affected zone, with a grain size of about 80±20 μm (Fig. 4a2-4a4).
It was worth noting that a large number of microcracks appeared at the grain boundaries between crystal clusters of primary α phase and secondary α phase in the overheated zone and melting zone (Fig. 4b1 and Fig. 4c1-4c2), and the extension direction was consistent with the grain boundary.
The primary α phase and secondary α phase crystal clusters were evenly distributed near an overheated zone, but a large number of secondary α equiaxial grains were distributed near a heat-affected zone, with a grain size of about 90±10 μm.

Grain boundary diffusion of Fe in high-purity copper Jens Ribbe, Guido Schmitz, S.
Divinskia Institute of Materials Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany a divin @ uni-muenster.de Keywords: copper; grain boundary diffusion; grain boundary segregation; molecular dynamics simulation.
Grain boundary (GB) diffusion of 59Fe in high purity polycrystalline copper was measured using the radiotracer technique and precision parallel sectioning in an extended temperature interval.
However, there exist generally a number of additional factors (e.g.
Gust: Fundamentals of Grain and Interface Boundary Diffusion, (Wiley \& Sons LTD, Chichester, New York, 1995)

Grain size and Hardness of tested steel at different cooling rate.
The grain size of the tested steel were measured with average cut line method under different cooling rate, the curve of relationship between grain grade and cooling rate shows in Fig. 4.
The result indicates that the grain grade increases and grain size is fine with the increasing of cooling rate of Nb-Ti micro-alloyed s D460 ship plate steel.
When cooling rate is 0.5℃/s, the grain grade is 8.5; when cooling rate is 23℃/s, the grain grade is 12.
At lower cooling rate region, the reason is that Ferrite critical nucleation size decreases with increase of grain core number, the grain growing was restrained after phase transformation and cause the grain refined; at higher cooling rate region, the reason is that the early occurrence of Bainite transformation refines the γ grain and make later occurrence Martensite refine.

The grain size effect was not noticeable because the selected grain sizes were much larger than that of the micro feature.
There are a number of surface patterning methods that can chemically and physically modify surfaces but many of them do not have high production efficiency and economy characteristics.
Considered factors Forming steps [number of steps] Forming velocity [µm/s] Grain size [µm] Friction coefficient Values 1, 2 0.5, 1.0, 1.5 25, 60, 100 0.05, 0.10, 0.20 Results and Discussions The example results of the microimprinting simulations are shown in Fig. 3.
In Fig. 4(b), the variation of grain sizes barely affected the peak errors because the feature size of the micro pattern was much smaller than those of the grain sizes.
Selected grain sizes did not affect the peak errors.

The grain size and lamellar spacing obey a parabolic law.
The alloy exhibits mainly a uniform near lamellar (NL) structure with a large number of lamellar colonies composed of γ-sheet spaced by α2-sheet.
It should be noted that there is a random distribution of the borides showing white ribbons or particles in both grain and grain boundary.
Thus, the number of γ phase nuclei increases, the size and amount of γ phase gradually increase with increasing content of tungsten.
Acknowledgements This research was sponsored by the National Natural Science Foundation of China (project number 51201141).

In addition, it is an alternative grain refinement approach that , nanoscale twins can generate nanosized grains[11].
Apparently, twin thickness, in addition to the number of twins, is a crucial structure parameter for the twinned materials.
A number of researches have shown that the improvement in mechanical properties and fatigue life of the stainless steel was directly related to the generation of dislocations and micro-structural deformation near the surface during the LSP process [14].
The grain size was determined to be 2μm～5μm, the average grain size is about 3.2um shown as Fig.2(b), the grain boundary (GB) is distinct and few twins can be seen in it shown as Fig.2(a).
It can be clearly seen from Fig. 5g and h that there are a large number of MT–MT intersections in three directions.

The influence of the grain material, grain volume VG, grain size according to FEPA, axial feed faA, number of starts z0A and cutting speed vcA can be seen in Fig. 4.
The number of starts has the third biggest impact with approximately 15%, followed by grain material and grain volume with 10% and 7%.
The effect size of the number of starts and the grain material is clearly influenced by interactions with other parameters.
In the analogy trial each grain machines the same volume, but the number of cuts and the undeformed chip geometry are different.
The transferability of the influence of the number of starts to generating gear grinding is therefore not directly possible, because depending on the number of starts z0 during generating gear grinding the number of grains which are used for grinding a tooth gap varies.

It is shown that friction stir welding provides a fine-grained structure of the weld.
The weld zone of Al-Cu alloy consists of equal size grains, with intermetallic particles located along the grain boundaries.
Along with the above features of second-phase particle distribution, the weld structure contains a small number of voids up to 2 to 20 µm in size (Fig. 4) whose formation is related to a vortex-like flow of the material.
The structure of metal in the AMg5 alloy weld is inhomogeneous (Fig. 7): it is more fine-grained near the base metal at a depth of about 100 µm, followed by a band with coarser grains (indicated by arrows in Fig. 7,a), and then becomes fine-grained again.
Acknowledgements This research was carried out under project number 02.G25.31.0063 of Ministry of Education and Science of the Russian Federation (Resolution No.218 of the Government of the Russian Federation).

The number of electrophysical methods of processing, according to the methods of influence, are attractive and fit into the efficiency concept.
Due to re-crushing, the specific surface area of ​​the cement grains exposed to re-crushing is increased approximately 1.5 to 2 times [1].
In this case, the change in the acting force on the cement grains depends on the coefficient of the cement mixture normal density.
From all the above mentioned, it can be concluded that for a certain intensity of the external field the developed force in the cement grains reaches a critical value at which the adsorption layer of the cement grain breaks down, and, consequently, additional contacts of the minerals of the cement grain with free water appear, i.e. the relationship between the surface and the volume of the phase changes.
Assuming a number of assumptions (cement particles having the surface of a ball are uniformly distributed in volume, the same size, and that dispersed systems have maximum stability with the most dense packaging), proceeding from the fact that the destruction of cement grains as a result of electrostatic forces at the interface «cement grains - hydrated shell» occurs along the lines of force of the field, it is possible to assert about the destruction of grain by diameter.