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Internal dislocation structures were studied in the near surface region; microbands that sometimes extend over several grains were found at approximately 45º of the tensile axis on ferrite grains.
The volume fraction of austenite is approximately 50% and the average austenitic grain size in the plane perpendicular to the specimen axis is about 10 μm.
All of them grow linearly with the number of cycles and almost at the same rate.
a) b) Fig. 3: Dislocation structure in the near-surface region at rupture: a) dislocation bands in the α grain; b) micro-bands developed at 45º from the tensile axis in the ferrite TEM Observations.
a) b) c) d) e) Fig. 4: a) SEM image showing the distribution of slip bands in both phases; b) aspect of a α/g grain boundary imaged with the AFM signal error to evidence the topography of the electropolished material; c and e) details in the austenite and ferrite are shown in 3D images relate to the zone presented in d).

Moreover, local values of the average grain size of the material were measured showing the microstructural evolutions undergone by the material due to the extrusion process.
In this manufacture typology, the material is divided according to the number of mandrel legs; afterwards, a welding chamber is used to rejoin the material [1].
Anyway, die shape is just one of the variables that strongly affects the welding strength of the joint lines; in fact, many other parameters have to be considered, too, like: extrusion ratio, portholes number, extrusion speed, bearing length and billet temperature [5].
It should be observed that, even if the material grains are clearly discernable just a slight difference of the average grain size is measurable: actually material in zona A (average grain size: 10µm) showed an average grain size just a bit larger than in zone B-C (6µm).
Fig. 3: Material microstructure in zone A Fig. 4: Material microstructure in zone B-C Further investigations are needed in order to determine clear relations between the different material paths and the local values of the average grain size.

To produce nanoceramics by SWL, the initial coarse-grain oxide was placed in a sealed spherical steel case.
The samples were characterized by X-ray diffraction, and a number of samples were examined using scanning tunneling microscopy and scanning electron microscopy.
A defect concentration in nanooxides is significantly more than in single crystals or coarse-grain polycrystals.
The absorption spectra of such a coarse-grain ceramic almost coincide with the spectra of single crystals.
This is associated with increasing the function k(E) due to the scattering on nanocrystallites and by increase in the number of defects.

The latter mechanism sharply intensifies by grain fragmentation down to nanostructuring under conditions of α«β phase transformations.
Treatment of measured data, that is construction of texture pole figures (PF) and determination of their parameters, was carried out by the software, including a number of specially elaborated programs.
Deformation development can be either crystallographically regulated, as in the cases of crystallographic slip in grains of a-Zr and β-Zr, having HCP and BCC crystalline lattices, respectively [2], or realized by a non-crystallographic mechanism as in the case of mutual displacement of grains by interphase boundaries within a fine-grained mixture of two phases under conditions of a«b transformations Fig. 3.
Since preheating does not result in the complete α→β PT, new-arising grains of β-Zr are separated from each other by α-Zr streaks and therefore the sample deforms as a polycrystal, characterized by some mutual mismatching in behavior of neighboring grains.
However, many samples after deformation at 670o and 730oC display textures, clearly originating from ideal orientations of β-Zr grains, as if the majority of initial α-Zr grains experienced PT α↔β in spite of a relatively low deformation temperature (Fig. 2-d,h).

Influence of the Friction Factor on the Temperature Field in Upsetting of a Perfectly Plastic Strip under Plane Strain Conditions Lihui Lang1,a*, Sergei Alexandrov2,b and Wiktoria Mishuris3,c 1-2School of Mechanical Engineering and Automation, Beihang University, No. 37 Xueyuan Road, 100191 Beijing, China 3Department of Mathematics, Institute of Physics Mathematics and Computer Science, Aberystwyth University, Penglais, Aberystwyth, SY233BZ, Wales, UK alang@buaa.edu.cn, bsergei_alexandrov@yahoo.com, cwim@aber.ac.uk  Keywords: temperature. friction factor. continued compression. fine grain layer.
A fine grain layer is often generated in the vicinity of friction interfaces in metal forming processes.
Temperature and plastic strain are responsible for the generation of narrow fine grain layers in the vicinity of frictional interfaces [3].
Acknowledgment WM was supported by the FP7 EU project TAMER (grant agreement number: IRSES-GA-2013-610547).

When no MgO was doped, the grain size reached above 200μm.
When the MgO content was 1.0wt%, the grain size was around 20μm.
MgAl2O4 impeded the rapid growth of Al2O3 crystal grains in the late stage of sintering, playing a role in reducing the grain size.
With the increase of MgO content, the grain shape also changed.
The decrease of the ion pair number in unit volume will decrease the dielectric constant.

The best strength and deformation properties have concrete with grains DMA=10mm and 8-15% of grains 5-10mm.
It should be noted that the special energy state of the new surfaces of crushed mineral materials is due to the formation of a large number of unsaturated valence bonds.
The required composition and the number of additives is established experimentally in construction laboratories.
M. high-Strength concrete for fine-grained constructions.
M. high-Strength concrete for fine-grained constructions.

The processing of alloy on 7A55 is difficult because a considerable number of particles remain in the alloy after conventional solution processing due to its high alloying element content close to the limit of solid solubility in the Al–Zn–Mg–Cu system [22], and those remnant particles degrade the age hardenability, aid corrosion, stimulate nucleation of new grains aid crack initiation and propagation and cause variable properties.
Just a small number of recrystallized grains are found in the as-rolled condition.
A large number of low angle boundaries exist in this condition, and they form into lots of subgrains with size of 3~10μm inside the elongated large original grains.
Figure 4 shows the area fraction of recrystallized grains in different conditions.
Coarse particles are easily formed on the grain boundaries during ageing.

The size of the grains was measured with the Jeol Smile View program.
The numbers of ALD process cycles are indicated at the top.
On the other hand, the grains formed with higher number of ALD cycles, form elongated, elliptical crystallites.
In this case, the maximum size of every grain was determined by measuring the distance between the two most distant points on the grain and making the statistical average over 100 grains.
The average grain sizes and film thicknesses of ZnO/Si samples Number of ALD cycles 25 50 90 130 258 430 Average grain size (nm) spherical grains 5.48 7.74 9.73 11.53 - - elliptical grains (max length) - - 18.83 27.40 29.65 41.29 Film thickness (nm) 6 11 20 29 54 100 Further information on the chemical composition was obtained from the XPS measurements.

A large number of synthesis methods of titanium dioxide have been investigated and reported in the literatures [10-13].
The average grain size is about 10 nm.
They obtained anatase with grain size of 25~66 nm.
In our work, nanophase anatase with average grain size 10 nm was synthesized very rapid under microwave irradiation condition.
TEM investigation indicates that granulous and well-dispersed TiO2 is obtained, with average grain size of 10 nm.