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It is revealed that the direction of microcrack propagation changes at austenite grain boundaries as well as at substructure elements within the grain.
Numbers of researches [3-8] indicate that propagation of cracks the above dimensions are characterized with considerable deviations and the latter is most intensive at initial stage of crack growth.
Consequently, the effect of local anisotropy of grain is neglected [9].
Notwithstanding the number of experimental result on microcrack propagation direction variation, there is no valuable hypothesis explaining the real reasons of the existent process.
The microcracks with long, parallel edges are mainly found inside grains.

Journal Title and Volume Number (to be inserted by the publisher) 3 Fig. 2.
Evolution in the grain size as a function of annealing time.
Then the grains start to impinge and with increasing Vv a larger and larger fraction of the grain surface areas are neighboring other recrystallized grains (and not deformed matrix material) whereby Sv decreases.
Molodov: Grain Boundary Character - A key factor for Grain Boundary Control.
Proc Recrystallization and Grain Growth, ed.

During the microscopic analyzing the identified situations carefully was observed the fracture surface nearly all the pores were located between the grains and the determined average grain diameter was 9,5 mm.
The change in fracture mode with grain size (Dm) shown in figure 6, did not result from a possible change of physicochemical properties of grain boundaries during sintering.
For small grains of PZT, in contrast, the formation of polydomain structure within the grains may not occur.
If the number of domains in grain is very limited or the single domain structure is formed because of small grain size, the dominance of intergranular fracture is predicted.
The results may imply the internal stress at grain boundaries is developed by poling as a consequence of reduction in the number of domains in a PZT grain.

The 5 phases comprise the extradendritic melt, the solid dendrite and interdendritic melt inside the equiaxed grains, the solid dendrite and interdendritic melt inside the columnar grains.
The calculation starts with following initial conditions: Tinitial = 314.15 K, =10-5, = 10-5, and the number density of equiaxed crystals of 10+5 m-3.
Using a grid 10 times finer than the present one, Kharicha et al. ‎[20] predicted higher number of plumes at the bottom columnar tip front.
Ludwig, Modelling Mixed Columnar-Equiaxed Solidification with Melt Convection and Grain Sedimentaion – Part I: Model Description, Comp.
Bührig-Polaczek, Grain nucleation parameters for aluminum alloys: experimental determination and model validation, Metall.

Values ε and ∆d/dav characterize elastic deformation of the crystalline lattice at different scale levels - at the microlevel of grains with the definite orientation and at the mesolevel of grain groups, representing the texture of material, respectively.
As the number of ECAP passes increases, some fractions become notable in distributions in the form of separate peaks.
The latter results in arising of new fine grains and proves to be an alternative mechanism of grain comminution, along with inevitable fragmentation of initial grains in the course of their deformation and reorientation.
In both Cu and Ti rods the substructure anisotropy decreases with the number of ECAP passes and in most grains some perfection of the crystalline lattice takes place.
The most probable value of dislocation density ρ for Cu rods varies in limits 1x10 13 ÷ 1x10 14 m-2 and decreases with the number of ECAP passes (Fig. 2).

The limited number of active slip systems in hexagonal close packed (hcp) crystal structure of magnesium leads to particular deformation characteristics in wrought components.
From Fig. 3a it can be stated that the AZ31B alloy billet underwent a moderate grain coarsening during heating and holding at high temperature, the grain size being 16.7 mm, which is slightly larger than the value of 15.3 mm corresponding to the starting material.
Hydrostatic compression stress state in the billet container apparently promoted the generation of twins within the grains.
Recrystallization readily occurred at grain boundaries under the effect of plastic deformation of the extrudates.
Although the concurrent action of temperature and strain also promoted the abnormal coarsening of a few grains in the transition region, the completion and possibly repeated process of recrystallization resulted in a fine and relatively equiaxed grain structure in extruded tubes.

If the passage of time on the oxidation number of drawings, you can get a typical parabola graphics, which reflects the SiO2 protective layer on SiC oxidation rate impediment.
Doping amount of B, B is in the process of sintering SiC grain boundaries, some of the SiC to form a solid solution, thereby reducing the grain boundary energy of SiC.
Study abroad SiC mainly focused on the liquid phase sintering, the sintering aid with a number, at a lower temperature to achieve densification of SiC.
SiC is a very strong covalent bond, resulting in the volume of the sintering and grain boundary diffusion rate is rather low; SiC grain surface of the SiO2 film, but also play the role of a diffusion barrier.
But the process can only be prepared sintered SiC parts simple shape, and a sintered product prepared in the process number is small, it is not suitable for industrial production.

Wave� number (cm-1) R1 R2 5975 6025 6075 6125 6175 (a) Intensity (a.u.)
Wave� number (cm-1 ) 100 300 500 700 (b) 120 140 160 180 200 It147 Im178 Im188 Intensity (a.u.)
Wave� number (cm-1) R1 R2 5975 6025 6075 6125 6175 (a) Intensity (a.u.)
Wave� number (cm-1) R1 R2 5975 6025 6075 6125 6175 (a) Intensity (a.u.)
The amount of the monoclinic fraction depends on the relation between grain size and binding force.

Thus, multi-layers were deposited by increasing number of coating.
The refractive index is obviously raised with increasing coating number of TiO2 layer.
It can be seen that the grain size of TiO2 film is around 15 to 20 nm and these grains are not agglomeration.
Besides, these grains also show high dispersion and distribution in surface of film.
Al- though the grain size in sintering temperature at 500°C is similar to the grain size in sintering temperature at 200°C, these grains show a high aggregation.

Pressure Subsystem Speed Subsystem Computer Fig.1 The sketch map of system 1.spindle of machining center 2.grinding device 3.grinding wheel 4.curved surface workpiece 5.workbench 6.DC electric 7.Thin film cylinder De\µ m N/ Number of times 3 4 2 1 No. 180 and No. 240 grain sizes and two ceramic, resin bonded wheels are chosen for grinding.
N/ Number of times 4 2 3 1 Ra\ µ m 1.180 size ceramic bonded grinding wheel 2.240 particle size of resin bonded grinding wheel 3.240 size ceramic bonded grinding wheel 4.180 particle size of resin bonded grinding wheel Fig.2 The variation tendencies of processing effect and grinding times From the finer, the finer the grain size of the grinding wheel is, the smaller the grinding removal amount is, the lower the surface roughness value is.
The grinding wheel with finer grain size has larger amount grain size grinding simultaneously.
The surface roughness mainly relates to grain size of the grinding wheel and grinding fluid.
Ackonwledgements: Supported by Liaoning department of education Subject number :2008089 References： [1] Oguchi T, Hara M, Grossman M,Yamamoto S.