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The formation of MLTB structure and properties is simultaneously influenced by a number of technological factors: cooling rate, the temperature of casted metal, rotational velocity and etc.
With the increase in temperature of the pouring we can observe the coarsening of the matrix grain, apparently, due to the decrease in the rate of nucleation and deactivation of the impurity particles at overheating.
This can be accounted for the reduction of the average size of the lead grain and eutectoid grain during overheating.
When the temperature of the casting rises, the lead and eutectoid grains become refined, and the matrix grains coarsen.

Artificial Neural Network (ANN) is a family of models that are utilized to predict variables that depends on a huge number of inputs inspired by the way biological nervous system process information.
Unhydrated Cement Grain Unflocculated C-S-H layer Flocculated C-S-H layer Figure 3: Effects of Accelerating ions on the flocculation of C-S-H layer In the case of the samples having large dosage of accelerant, the C-S-H forming on the surface of the particles was more flocculated in the presence of large accelerant ions as shown in Fig. 3.
Figure 5: Microscopic configuration of Cement particle under the action of accelerator Very small needle like hydration product as shown in Fig. 5 form early with time and some hydration products seen to bridge spaces between grains, indicating that some formation are found outside the original grain boundary.
Fibrillar hydration products formed both outside and inside the cement grain [7].
This is also the reason why superplasticizers do not perform well in the dispersion property of samples since large formation of adsorption areas took place outside the cement grain.

This could lead to critical health and economical issues in a near future, considering the large number of zirconia femoral heads implanted during the last decade.
Different parameters can affect aging: an increase in the grain size accelerates it, as well as the presence of tensile internal stresses.
Both phenomena result in decreasing the stability of the tetragonal phase (bigger tetragonal grains are less stable, and tensile stresses provide mechanical energies that can be used to overcome the t-m transformation energy barrier).
Then a martensitic transformation towards the monoclinic phase takes place [8], first inside one grain, and propagates to neighbouring grains, following a nucleation and growth kinetics.
This critical content was related to the percolation threshold above which a continuous path of zirconia grains allowed transformation to proceed.

The metamorphic layer presents the character of denser tissue and finer grain.
As a result, the strengthened layer of No.4 specimen has more fine grain and higher dislocation density.
From the analysis above, the high strain rate makes material produces a large number of dislocations during grinding process due to the changes of grinding speed, depth of cut and feeding speed.
The strengthening and grain refinement make the ground surface hardness increase.
Meanwhile, the grain refining and the dislocation density increase.

In recent years, in order to improve the strength the steel, Mo, V, Ti, Nb and other rare metals were dissolved in the standard Mn18Cr2 by micro-alloying[3,4], modification, grain refinement , precipitation hardening and other methods were used, and obtained a good result at last.
It can be seen from the images that there are many high density dislocations in austenite grain and many nanoparticles on the dislocation line.
The analysis of electron diffraction pattern shows that TiN particles exist in the austenite grains, and have a good interface matches with the austenite.
The existing of TiN nanoparticles in austenite matrix produces a large number of dislocations, which also improves the hardness and strength of the steel.
TiN particles exist in austenite grains, and TiN particles have a good interface matches with austenite.

The HAZ was not expanded by the number of heat treatments.
Shackelford, ’Method of Producing Ultrafine Grained Steel’, 1963, US patent 3, 178, 324
Shackelford, ’Method of Producing Fine Grained Steel’, 1966, US patent 3, 278, 345
Morris, Jr., ‘Thermal mechanisms of grain and packet refinement in a lath’, ISIJ International, 1998, Vol.38, No. 11, pp. 1277-1285
Nakashima, 'Improving rolling contact fatigue life of bearing steels through grain refinement', 2004, NTN technical review, Vol.71, pp. 2-7

The crystalline grain size of the banded structure is 7-grade according to the National Standard of GB /T 6394-2002, which satisfy the requirement.
However, the size of the crystalline grains are different, showing the state of mischcrystal.
The grain boundary is black and there are no some granular carbides with large-scale size caused by the spheroicizing annealing processing in Fig.5.
The tempered temperature, time and times are not enough judged by the metallurgical structure of MT and the number and size of the disperse carbides.
Meanwhile, the aliguation of the alloy elements in the mould causes the different grain size and mischcrystal phenomenon.

The production of large-area graphene by chemical vapor deposition (CVD) on catalytic Cu has been attempted recently [2].Nevertheless, the obtained graphene are typically polycrystalline, mainly origin from the random nucleation of graphene grains and coalescence in dissimilar orientation [3].
Graphenenucleation have been discussed in several studies, arguing that graphene nucleates at grain boundaries, step edge, impurities and other surface irregularities[4].
The Cusurface contains grain boundaries, annealing twins and many other structures after high temperature processing.
The graphene’s number of layer and quality can be quickly characterized by Raman spectroscopy.
[3] Yu, Q., et al., Control and characterization of individual grains and grain boundaries in graphene grown by chemical vapour deposition.

Achieved mechanical properties of material with grain size ASTM 12 are in Table 1.
The microstructure consist of light gray blocks of carbides and fine lenticular and lamellar particles of delta phase (Ni3Nb) distributed in the FCC matrix, with grain size approximately 10 µm and a few deformation twins.
With decreasing stress level, the number of initiation sites decreases, Figure 3b, controlled by crystallographic slip at surface grains and static tensile final fracture area increases.
At higher stress level, Figure 3e, a few secondary cracks have appears whose are perpendicular to main fatigue crack propagation and probably are situated at grain boundaries.
Fractography analysis shows that at higher stress level fatigue crack initiates from a multiple sites and with decreasing of stress amplitude crack initiation sites are reduced into a single one controlled by crystallographic slip at surface grains or massively oxidized areas.

The proposed matrix will be evaluated in terms of economy, especially in light of fine-grained material used.
The fine-grained aggregates of the fraction 0/4 mm from the sand quarry in Zálezlice were used as filler.
The micronized limestone with a grain size 0-0.125 mm was used as filler to fill the gaps in the microstructure of the cement matrix.
Parameters Unit Quantity Number of fibers on spools [pieces] 24000 Diameter of one fiber [μm] 7 Tensile strength [MPa] 5100 Young’s Modulus of Elasticity [GPa] 245 Ductility [%] 2.1 Density [kg/m3] 1780 Amount of sizing [%] 2 Fig. 1 A SEM image of carbon fibers (left), carbon microfibers (right).
Conclusions The paper compares the selected properties of the samples based on fine-grained cement matrix reinforced by alternative carbon microfiber reinforcement.