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The pitch controlled by the magnification of the SEM and the number of scanning lines is about 5 µm in this particular case.
A strong localisation of the deformation occurs along bright lines on the micrograph, which are likely to be grain boundaries (Figure 5a, mark A).
Strain heterogeneity within each phase of the DSS may be due to crystallographic effects between grains.
The effect of grain interaction is also clearly shown in Figure 5 where the presence of a triple point has created a large strain concentration due to the incompatibility of plastic deformation between grains with different orientations.
They also form the basis for the validation of scale transition models such as finite element models or self-consistent models which take into account phase or grain interactions.

A number of scholars in recent years devote themselves to explain the mechanism of volume effect[11].
It can be seen from the figures that the grain nearby the section of the sample in conventional extrusion conditions that has almost no deformation.
While the grain around section of the sample of ultrasonic extrusion is smaller than the one under conventional extrusion, the deformation is also very large and parts of the grain boundary start becoming dim.
The deformation of the microstructure appears fibrous, and dim grain boundary, which shows the sliding movement of materials in plastic deformation easily occur between grain and grain after the superposition of ultrasonic vibration, and deformation get more smooth.
Conclusions 1.The experimental results of ultrasonic extrusion of different amplitude and conventional extrusion show that the polishing impact of ultrasonic vibration plays dominant role when load is heavy; ultrasonic vibration makes material “softening”, and softening effects of different material are also different. 2.The observation results of metallographic structure of conventional extrusion and ultrasonic extrusion hollow section shows that ultrasonic vibration can destroy grain boundary tissue of metal, smoothing the intracrystalline and intergranular deformation, which reduces the load of plastic deformation, slowing down the work hardening, and materials in plastic deformation get better. 3.The results of finite element simulation show that the difference of mechanism of shaping under the conditions that low load and heavy load after superposition of ultrasonic vibration.

That situation remained over a number of hours before setting.
At progressing hydration, cement particles are growing and hydration products are formed directly on the cement grains and in the inner core of the original cement grains.
An external layer of hydration products is thus formed on some parts of some of the cement grains.
Other cement grains remain unhydrated because they are fully covered by the polymer.
The polymer film can partly or completely envelop a cement grain.

After the heat treatment, (γ + γ') eutectic disappeared and M23C6 carbides precipitated mostly in the grain boundary (as shown in the Fig .1b).
In addition to the MC carbides, a lot of tiny stripe-like M23C6 carbides precipitated in the grain boundary in B alloy (2Re) and C alloy (4Re).
Numbers of M23C6 carbides precipitated in the grain boundary.
The grain boundary made it easier for the nucleation of M23C6 carbides, which explained why most of the M23C6 carbides existed in the grain boundary.
After heat treatment, M23C6 carbides precipitated in the grain boundary.

This steel is developed by a thermo-mechanically controlled process (TMCP), which produces fine-grained microstructure.
Grain refinement is the mechanism to improve both the strength and toughness of the steel, and these are essential properties required for structural applications [1].
Further, the coarse grains develop and degrade the impact toughness.
The number of passes required is ten passes for LNi1 and eight passes for HNi1, respectively.
The HAZ microstructures of LNi1 and HNi1 revealed that grain growth develops at higher heat input, whereas HNi1 has larger grains than LNi1.

The high SC characteristics of the SPS-processed MgB2 are considered by the authors to be due to the presence of MgO nanoparticles and to dislocations uniformly distributed inside the MgB2 grains.
In contrast, a number of spectra for this sample were obtained by Raman spectroscopy.
No correlations between the grain size, oxygen content, and jc of these materials were found either.
The oxygen segregation favors the formation of clean MgB2 grain boundaries because of locally reduced impurity oxygen content.
The nanograined structure of matrix and pinning centers (Mg-B-O inclusions and grains or boundaries of higher borides) are responsible for the high critical currents in these materials.

It is shown in Fig.3(a) that the alloy casting is a coarse columnar crystal in the absence of an electromagnetic field, and the grain size reaches 200-300 μm.
The grains are equiaxed with a size of 60-150 μm (as shown in Fig.
After homogenizing the alloy, the distribution of Cu, Ni, Fe and Mn in the matrix is uniform in the grain interior and boundary.
The SEM line scans of Cu-10Ni-Fe-Mn alloy DC casting and homogenized casting elements (a) Common cast specimen; (b) Homogenized specimen Fig.8 shows the composition distribution from the grain boundary to the grain interior before and after the homogenization of the main alloy elements in the alloy DC ingot.
This relates to the properties of an alloy, the type of solid solution, composition, grain size and temperature.

The resulting unstable layer of graphite causes the premature removal of diamond grains from the metal matrix [22,22-26].
Diamond grain with mass ≈0.03 car was set so that its polished side snug against the pressed rod from the side of chromium.
Grains were stacked in three layers with 16 pieces in each one.
For this purpose, the diamond grains were wrapped with a plasticizer using finely dispersed chromium particles, so that chromium formed a shell around each grain before stacking in cemented carbide batch.
The linear wear of the grinding wheels was measured, the volume taken with diamond pencils was calculated until all diamond layers were completely worn out; and the specific productivity q (the ratio of the volume of the grinding wheel taken in a certain number of dressing cycles to diamond component mass of pencil worn in this process) as the main operational index of the functional properties of the pencils was determined.

The structure of steels 04Cr22Mn17Ni8Mo2VN and 07Cr20Mn9Ni8MoVN respectively with 0.548% and 0.397% nitrogen in the quenched state from 1100 °C consisted mainly of austenite with a grain size of 100 and 30 μm.
In steel 04Cr22Mn17Ni8Mo2VN, a small amount of the s-phase was also observed, mainly along the grain boundaries, and d-ferrite – at the grain boundaries, twins and inside the grain.
Carbonitride V(C,N) particles have different sizes and uniformly distributed inside grains and predominantly have a regular shape. 2.
Nitrides Cr2N mainly nucleated on carbonitrides located along grain boundaries and incoherent boundaries of g-twins. 5.
The authors of [19] studied a number of stainless Cr-Mn-steels and determined that Mn, at least at low nitrogen and carbon contents, behaves as an austenite-forming element.

Thick-film form of mixed spinel-type manganites restricted by NiMn2O4-CuMn2O4-MnCo2O4 concentration triangle has a number of essential advantages, not available for other ceramic composites [4-6].
Within the above system, the fine-grained semiconductor materials possessing p+-type Cu0.1Ni0.1Mn1.2Co1.6O4 and p-type Cu0.1Ni0.8Mn1.9Co0.2O4 conductivity can be easily prepared.
Micrograph reveals grains of basic ceramics, surrounded (“covered”) by glass and pores.
Thick films show higher density and microstructure homogeneity with uniform distribution of grains, glass additives and pores.
This effect is supposed to be connected with thermally-induced compression of thick films and diffusion of metallic Ag into the grain boundaries.