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It is found that the plastic deformation occurred unevenly and limited in single grains, shown by micro extruding steps at grain boundaries.
Some long twinning bands curved to accommodate the strain at grain boundaries.
It is seen that by the progress of the plastic deformation the clash between grain boundaries and twinning bands happened frequently, and the micro cracks initiated at such sites, some of them propagate along the grain boundaries or/and boundaries of twinning bands.
(4) In a lot of areas all grain boundaries pushed out, and some interfaces of twinning bands pushed out, too. (5) New micro cracks nucleated from very early plastic period, i.e., the number of the micro cracks increased with the deformation.
Micro cracks form in the intersections of grain boundaries and twinning bands, and of twinning bands.

Introduction The abrasive processing is the primary processing technology of ceramic materials, but the purity of the abrasive grains will impact surface quality of the workpiece, now the semi-fixed abrasive processing is proposed by the authors [1].
It has the good processing characteristic, which integrates with solid abrasive processing and free abrasive processing technology, and it can reduce or even eliminate the defects induced by large abrasive grains in the grinding due to its 'trap' effect.
In simulation, the indenter is imagined as large abrasive grain, and the SAP is soft, which can be embedded the indenter under processing velocity.
Table 1 Model parameters number d [µm] Density [kg·m-3] Kn [N·m-1 ] Ks [N·m-1 ] µ particle 2511 3～3.75 2970 5.0×106 1.1×106 0.9 Wall 4 - - 1.0×10 7 1.0×107 0.5 porosity pb_kn [N·m-3 ] pb_ks [N·m-3 ] pb_rad pb_nstren [N·m-2 ] pb_sstren [N·m-2 ] particle 0.22 5×10 10 5×1010 0.5 1×108 1×108 Wall - - - - - - Table 2 Parameters of walls Wall5 Wall6 number 1 1 Kn[N·m-1] 1.0×1010 1.0×1010 Ks[N·m-1] 1.0×1010 1.0×1010 After producing the SAP, then the indenter can be generated by PFC, in simulation, wall5 and 6 are imagined as the indenter, and the degree of indenter can be also changed, and three kinds of angles are simulated.
Conclusions This paper preliminary studies of simulation on the indentation of large grain in the SAP, and the 'trap' effect of SAP is validated, and the size of large grain is an influence factor in the 'trap' effect of SAP.

A comparison between the grain structures shown in Figs. 3(a) and 3(b) indicates that the growth speed might be quite different for each recrystallised grain depending on the interface mobility and the stored energy.
After the recrystallisation grains become equi-axed again in Fig. 3(c).
In (b) recrystallised grains are highlighted by different colours and deformed grains in white with grain boundaries shown using black lines.
Recrystallisation nucleation sites were selected using the criterion: relatively high cumulative number of slip system activated during the previous deformation.
Resutls showed that it is possible to simulate the typical recrystallisation textures experimentally observed for rolled FCC and BCC metals using this nucleation criterion by choosing appropriate critical values although the number of possible slip systems for the FCC metal and the method of calculating the number of activated slip systems in this work are different to the ones used in literature.

The average grain radius is about 1µm. 3D Voronoi tessellations usually include large numbers of relatively small entities such as small Voronoi grid edges and faces which can result in a refined mesh.
The mesh refinements can increase the total number of elements and significantly increase the time needed for explicit computation.
Because the crystallographic grain orientations are random, grain will show elastic anisotropy [4].
Some cohesive elements are embedded into grains; others are embedded along grain boundary.
Kgrain and Kgb denotes the K value of grain and grain boundary respectively.

A large number of plant fossils, Danaeopsis fecunda, Bernoullia zeilleri, et al, are late Triassic common molecule, in which all plant fossils are members of Yanchang flora.
Large number of plant fossils indicates the subaerial sedimentary environments, such as river, swamp, et al.
Gray-green, dark green thin-bedded fine-grained lithic feldspathic greywacke 1.53m 3.
Gray-green thick-bedded with thin-bedded fine-mindium grained lithic feldspathic greywacke 7.39m 1.
Rounded mineral grains with rough surface show the river-dominated depositional environment.

Imagine a particular phase, with a very large number of grains in random orientations.
We then expect a large number of low angle boundaries between touching grains, and that will be reflected in the neighbour-pair histogram.
Time-lapse misorientation There are a growing number of in situ EBSD studies [17].
Given the number of minerals, there are likely to be many more relationships, and their effects may be cryptic.
There are a number of problems with this hypothesis, though.

Figure 1 (g), (h) of ZK60 and ZK60 +1.0 Y morphology of two alloy extrusion products, we found that both alloys extrusion occurred after dynamic recrystallization, which ZK60 alloy extruded After the abnormal grain growth, and grain ZK60 +1.0 Y Y rare earth alloy added after the relatively small, large grains mixed with very fine recrystallized small grains, which is mainly due to the black alloy ZK60 +1.0 Y reticular formation of crystalline zinc-rich phase was squeezed after crushing second phase particles and fine particles, pinning grains and dynamic recrystallization grain growth inhibition dual role, it can effectively refine rare-earth Y alloy ZK60 tablets.
Figure 1 (e), (f) ZK60 and ZK60 +1.0 Y for the two-state microstructure T5 alloy extrusion products, extruded products after aging treatment, ZK60 alloy grain boundaries within the grains and particles are precipitation, the grain boundary more clearly, after ZK60 +1.0 Y alloy after aging treatment, the organization tends to be uniform, fine recrystallized grains have grown little tendency to precipitate particles number obviously.
In the extrusion process, the alloy, rare earth alloy, magnesium can play an effective role in the modification, i.e., refinement of the grain structure, so that the average grain size is reduced, since the number of grain boundaries depends directly size, therefore, the impact of grain boundaries on plastic deformation resistance of polycrystalline starting directly reflected by the grain size.
Figure 1 (g), (h) shows that adding the refinement of rare earth alloy Obviously, an increase in the number of grain boundary dislocations motion by the resistance increases, thereby enhancing its mechanical properties, extrusions aging treatment dislocations generated during extrusion, sub-crystalline alloy beneficial compounds dispersed second phase precipitation, aging can be on the basis of maintaining the tensile strength, yield strength of the alloy greatly improved, so ZK60 +1.0 Y alloy extrusion products should adopt the artificial aging treatment.
Effect of grain refinement on tensile ductility in ZK60 magnesium alloy under dynamic loading [J].

The material stability under shear (jamming) is ensured by odd circuits of grains in contact that prevent the grains from rolling on each other.
Grains are made of spheres of radius Ri with i being the label of the individual sphere with arbitrary choice of the numbering since there is no intrinsic long-range ordering.
We define then an adjacency matrix A of size n × n, where n is the number of vertices.
The blue circuits have even numbers of links and the particles can roll freely on each other.
Powder and Grains 2009, M.

This large number of rolling steps is the main reason for the high cost of magnesium sheets.
Thus, it saves a number of rolling and annealing passes in comparison to the conventional rolling process.
There are worldwide a small number of industrial or laboratory scale twin roll casters installed at universities, companies and research facilities.
Standard metallographic sample preparation techniques were employed and an etchant based on picric acid was used to reveal grains and grain boundaries [7].
The large number of dendritic grains in the upper and lower regions of the strip is an indicator for a low degree of deformation during the rolling operation.

TEM studies confirmed that the structure ‘directionality’ increases along the number of passes.
The microstructure and the texture evolutions in the deformed and the recrystallized states were mostly investigated by SEM/EBSD in a number of samples deformed up to 2, 6 and 10 passes.
The number of applied passes had a strong impact on the global deformation behaviour and on the intensity of grain refinement.
The size of new grains close to coarse SPP is only occasionally greater than the average grain size, and their shape is nearly equiaxed.
The large grains resulting from intense grain growth were observed mostly in places far from the coarse SPPs.