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BaFe12O19 substituted sample shows a single semicircle at lower temperature and two overlapped arcs at 120 and 160 oC due to grain and grain boundary.
The electrical resistivity contribution by the bulk material (grain), grain boundaries or electrode can be identified from the arcs [3].
BaTiO3 phase was indexed based on the standard JCPDS data number 05-0626 for tetragonal structure.
R1 is much higher compared to R2 due to difficulty of the charges to move in the grain boundary compared to in the grain.
From 25 to 80 oC, the grain boundary relaxation peak frequency decreases with temperature but the Z“ value increases showing an increment in the grain boundary capacitance.

The average WC grain diameter was approximately 0.45μm.
So, the aggregate of several WC grains or coarse WC grain with sizes of 6 – 7 mm in diameter become the fatigue crack initiation site for the present fine grained WC-Co material.
Figure 6 shows the variation of crack lengths, 2a as a function of number of cycles, N.
(2) The aggregate of several WC grains or coarse WC grain with sizes of 6 - 7 mm in diameter become the fatigue crack initiation sites for the present fine grained WC-Co material.
(3) The fatigue lifetime can be approximated by the crack propagation life, and the number of cycles spent in crack initiation can be neglected

The model also explicitly tracks the precipitate populations at grain boundaries and in the grain interior.
There are a number of calibration parameters in the model that have to be found by fitting predictions to experimental measurements.
The calibration procedure is discussed in more detail elsewhere [1, 2].Grain Evolution Model The grain evolution model predicts the dynamically recrystallized (DRX) grain size and subsequent grain growth in the FSW--SZ.
These new grains will then be susceptible to grain growth, giving the final SZ grain size.
This grain growth is modelled using a simple classical grain growth model based on the mean grain size and a single (average) HAGB energy.

Due to the smallness of the grain size, these NS metallic materials are usually several times stronger than their coarse-grained (CG) counterparts [1-3].
Based on measuring more than 300 grains, the calculated average grain size from the relative number frequency is approximately 22 nm.
Sample Grain size [nm] RTTLN σσ /2 Ref.
On the other hand, due to the strength rise with decreasing the grain size - Hall-Petch relation, the absolute strength rise is much more remarkable at smaller grain size.
As the grain size is reduced to the nano scale, the grain boundary (GB) related activities, such as grain boundary sliding and grain rotation, start to contribute to the plastic deformation significantly [11].

AFM studies indicate that the grain size and surface roughness increase with the film thickness.
This is mainly due to the increase in average sizes of grains caused by the increase of film thickness coming from the increasing number of laser pulses.
Average diameter of grains and surface roughness of CdS thin films CdS thin films Avg.
This means that as the number of laser pulses increases the bandgap reduce.
AFM images indicate that the microstructure of the films surface consist of spherical shaped grains.

In the study process factors namely feed rate, speed and coolant were analysed to understand the effect on the surface roughness, percentage (%) of thickness reduction, grain size and hardness of the Aluminium (Al) sheet metal after forming.
In the study it is observed that, the surface roughness, percentage of thickness reduction, grain size and hardness, all are interrelated to each other and hence, it is necessary to employ statistical methods to predict these parameter’s dependency [3].
The obtained experimental results surface roughness, % of thickness reduction, grain size and hardness are tabulated below (Table 1).
Table 2 Model summary statistics for surface roughens, % of thickness reduction, grain size and hardness of incremental forming Source Standard deviation Mean R2 Adj.
The optimum search is then driven by the minimum tool path, in order to reduce the number of trials.

Also the acoustoplastic effect changes the kinetics of both dislocations and vacancies in the grain structure so that new secondary phases may precipitate in the vicinity of grain boundaries which are usually free of them and thusly possess lower strength.
It is common to identify three structurally different zones in the FSW joints on hot-rolled aluminum alloy sheets as follows: fine-grain stir zone (SZ) formed by the rotating pin, thermomechanically affected zone (TMAZ) with elongated coarse grains oriented with respect to metal flow in the SZ, heat affected zone (HAZ) and base metal (BM) with grains elongated with respect to rolling direction (Fig.2).
It follows from the results in Table 1 that mean solid solution SZ grains of both samples are of almost the same size.
The microhardness testing shows that UAFSW sample has more uniform distribution of hardness numbers across the zones (see Table 1) as compared to the FSW one and therefore this weld seam is more balanced in terms of strength.
At the same time the mean size of S-phase particles in FSW sample is lower by a factor of 1.7, i.e. these particles are distributed in higher number of grains.

This will allow to save metal, reduce the required deformation force, costs of labour and energy due to reduced number of passes of the metal through the working stands.
That is, the use of this tool provides a fine-grained isotropic structure in the volume of deformed metal.
The maximum difference in the number of slip lines when comparing longitudinal and transverse cross sections is observed after rolling of brass billets in smooth rolls (fig. 5).
Visually, this is reflected in the fact that within some grains of the glide lines of dislocations more than the other (fig. 5 a,b).
After rolling in the relief rolls, this is not observed, the distribution of slip lines within individual grains and in the other direction is uniform (fig. 5 c,d), i.e. all the grain in a relatively equally involved in the gliding of the dislocations, and, consequently, in the plastic deformation.

There are a large number of small particles on the grain surface, the size of small particles is about100nm.
However, the morphology of biomorphic ZnO is not the ideal hexagonal prism, and there are a large number of small particles on the grain surface.
There are a large number of small particles on the grain surface, the size of small particles is about 100nm.

The refinement of original grains was observed.
Number of passes are applied to the specimen resulting in a variation of crystallographic during the procedure by the strain accumulation [2-7].
Ferrite content was estimated terms of extended ferrite number (EFN) using Fischer ferrite scope.
There is significant reduction in the grain size.
The initial average grain size was 15.4 µm and after ECAP the grain size is 11.2 µm. 25µm 25µm a b Fig.3.