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In the case of nanometric manufacturing, the cutting depth is far less than the average size of the single crystal grain which composes the polycrystalline materials, so generally the manufacturing process is carried out with the single crystal grain along specific crystal orientation.
The static boundary atoms in the workpiece and all of atoms in the grinding grain are fixed to the rigid base of the workpiece.
As the x (grinding direction) y z Newtonian Atoms Thermostat Atoms Boundary Atoms Journal Title and Volume Number (to be inserted by the publisher) 363 temperature is in proportion to the kinetic energy, the energy of these layers should be constant.
But in the course of nanometric manufacturing, the depth of cut is an extremely small fraction of the average grain size; this manufacturing process basically involves grinding within a single grain or single crystal at periodic interruptions on the grain boundaries.
When turning is required, the workpiece with ultrafine grain size and random crystallographic texture would be preferred.

It is composed of two different types of grains.
These are pure γ(TiAl)-grains and grains with γ and α2(Ti3Al) or β(Ti) phase constituents.
The second type of grains, on the other hand, seems to be nearly undeformed.
The respective spot numbers are indicated.
The stripe-patterned grains have the overall composition of about Ti-44Al-5.7Nb.

Hence, joints welded at tool rotation speed of 1200 rpm showed coarse – grained microstructure and low mechanical properties.
Typical microstructure of the cross-section of FSW joints is illustrated in Fig. 3.The base metal microstructure consisted of large elongated grains typical of a rolled structure, with an average grain size of 80μm (shown in Fig. 3a).
Grain size depends significantly on tool rotational and welding speed and applied load.
The increase in the hardness value of NZ is related to the extra-fine grained structure.
In the early stages of plastic deformation on FSW process , grain boundaries are important obstacles to slip, so fine-grained joints are stronger than coarse-grain joints [17].

Electrical properties of these materials depend on the morphology of microstructure constituents (grains, grain boundaries, domains...) whose evolution is a direct consequence of different synthesis parameters.
effect together with the increasing number of defects in the crystallite bulk leads to an overall increase of the amorphous phase in the activated product, changing the powder particle reactivity.
The second process includes sintering of grains between aggregates and the heating rate increases.
Intensification of transport processes, which result in polyhedral grain shapes also bring about an increase in the number of contact necks and strengthening of boundary regions of neighbouring grains, primarily in regions inside agglomerates (Fig. 6b).
Microstructures of fracture surfaces of these samples show that fracture occurred both between grain boundaries and through grains (Fig. 7a).

Side milling Ti6Al4V titanium alloys with fine grain carbide cutters is carried out.
And the use of carbide cutters with fine (ultra fine) grain is becoming a new trend for machining of titanium alloys [7].
It is made of fine grain carbide and is specially designed for machining of titanium alloys.
From Eq.2, it also can be found that with specific values of teeth number, radial cutting depth and feed per tooth, the average cutting thickness is not relevant to the cutting speed.
Summary Side milling Ti6A14V with fine grain carbide cutter is conducted and the effects of cutting parameters on surface roughness are investigated.

In order to obtain information of the grain substructures of the broken samples, crystal orientation maps were performed close to the fracture edge.
The ferrite grains show a recrystallized and recovered morphology with an average grain intercept length along RD of 11.13 ± 2.29 µm for the quenched sample and 10.23 ± 1.75 µm for the slow cooled sample.
Although the different cooling rates of the samples show a small influence on grain size, the amount and type of constituents are affected.
In both DP steels, grains substructures such as dense dislocations walls and microbands are observed within the ferrite grains, as can be seen in the case of the slow-cooled material in Fig. 4a.
The difference in the coalescence mechanism of both DP steels relies on the number of points of fracture.

Although these methods are more close to the fact case, these need lots of number of thermal cycles to result in crack initiation and propagation.
The angle bisectors of gaps, i.e. the central lines of specimens were almost parallel with the growth direction of columnar grains.
Fig. 4 illustrates that the thermal fatigue crack initiates from the grain boundary and the maximum stress concentration point.
Some grain boundaries are shown in the edge of the notched specimens.
The cracks mainly initiate from these grain boundaries and extend to the internal along grain boundaries.

So having a finer mesh only at the core and coarser mesh beyond the core reduces the number of equations to be solved.
The initial number of nodal points and elements are 3466 and 14741, respectively.
The number of iterations for deformation was 300 per step.
Fig. 6 shows a change of grain size, where A is for as cast, B and C are at center and edge of the sheet, respectively.
The average grain size of as cast was 91.2� and that of extruded sheet at center was 36.2� and 24.8 � , respectively.

When starting from concepts of texture formation, it can be anticipated that grains of the deformed polycrystal differ in substructure conditions, determined by initial and final orientations, active plastic deformation mechanisms, affiliation of the grain to that or another part of the texture maximum.
Obtained data agree with above-mentioned results of experiments on rolling of Mo single crystals: the energy of lattice distortion, accumulated in grains of the texture component {111}<112> proves to be much higher than in grains of the component {001}<011>, and therefore the recovery in grains of the former component is accompanied by more significant changes of diffraction parameters than those in grains of the latter component, whereas their recrystallization temperature differ by 150-200o .
The latter is less distinct, since the corresponding area of PF contains comparatively small number of points.
Therefore at the periphery of texture maxima and in texture minima there are grains with spoiled crystalline lattice, whereas grains with relatively perfect lattice remain at the center of texture maximum and retain the symmetric stable position.
Grains with the too "spoiled" crystalline lattice lose the ability to deform by means of crystallographic mechanisms, so that their final orientations prove to be occassional; texture minima contain only such grains.

What’s more, when mixed with the air-entraining agent, freezing-thawing cycles number will have an obvious increase.When water-cement ratio is 0.35-0.39, the ability of frost resisting is very high but when water-cement ratio is larger than 0.39, freezing-thawing resisting performance is substantial decline.
Due to adding the nano SiO2 to cement concrete and the globular small particles of nano SiO2 filling in the voids in cement grains, and which will change the grain composition and particle size distribution efficiently.
The nano SiO2 used in test is selected in iron alloy factory with electrical dust method, which is light gray,density is 2.2 g/cm3,average grain diameter is about 100nm, specific surface area is 18238m2/kg.
In order to prevent too much decline of strength ,the air content can be controlled by the maximum grain diameter of coarse aggregate, for example, when the max value is 40mm,the air content should be controlled in 4%-5%.
Fig. 5 is the relationship of freezing-thawing cycling number and water-cement ratio when nano SiO2 is 10%,air-entraining water reducing agent is 0.5% when relative dynamic elastic modulus is 60%.