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When Im=3A, the grains get obviously refined as shown in Fig. 6 d).
It can be thought that when magnetic field current is 3A, the much finer grains in the plasma surfacing layer leads to the highest hardness and the least wear loss.
According to the solidification theory, the grain size of materials is mainly affected by the nucleation ratio.
Thus, the growth duration of dentrite becomes very short in the greatest heat dissipation direction, and the grain size gets significantly reduced.
Thus, the specific surface area of grain boundaries and the number of dislocations increase.

Boron segregates to the grain boundaries and improves grain boundary cohesive strength, this causes the effective suppression of pearlite and/or ferrite formation compared to other substitution elements [5].
Microhardness measurements were performed under 50gf loads by FM-700, and presented as Vickers hardness numbers.
No pronounced dislocation substructure was usually observed within the ferrite grains.
The lath bainitie structure [8] possesses the parallel ferrite with lath structure and numerous granule-like or rod-like cementites along and/or into the laths, and the prior austenite grain boundary network can be seen clearly (Fig.1f).
The reason is that straining leads to both an increase in the austenite grain-boundary area per unit volume as a consequence of the grain flattening and the formation of deformation bands or shear bands known to serve as potent ferrite nucleation sites.This suggestion appears to be supported by the significantly finer microstructures obtained in the present study after transformation from the deformed austenite, compared to the case of the undeformed austenite.

., the crack was located in coarse grained region of HAZ, and not in fusion line.
The crack was intergranular in coarse grained region, and ended at fine grained region of HAZ.
All above characteristics consisted with formation mechanism that the grain interiors were strengthened more than the grain boundaries.
Fig.2 .Crack tip point to coarse grained region from fine grained region Fig.3 .Branch cracks belonged to main crack in coarse grained region The formation of reheat cracks needs three essential requirements: sensitization tissue, appropriate temperature and stronger tensile stress [1].
The number of inspecting positions was not less than four for welding seam an for base metal and all inspection positions should be distributed uniformly along circular.

The properties and way of synthesis of bismuth titanate have been reported in a number of papers, [4-8].
As we already mentioned, by increasing the milling time, the grain size decreases.
When reducing the grain size, the quantum effects come to the forefront.
Asymmetry was more rendered in samples with smaller grain size.
In addition to reduction in grain size with the increase of milling time, effects were also noted (change of position, relative intensity and half-width of Raman modes), which indicate changes in the structure, caused by nanodimensioned grains.

Numbers of approached have been made to improve the wear resistance and surface hardness of DSS.
The formation of nitride at the layer happens because of precipitation of chromium with nitrogen in the austenite and ferrite grains.
It can be seen clearly that a uniform hybrid layer formed at the austenite and ferrite grains of the specimen.
Fig. 2(b) also shows formation of Cr2N at some area in the ferrite grains validate the outcome from the phase analysis of diffraction pattern of hybrid treated 2205 DSS.
Observation also shows the formation of nitride layer mostly occurred at ferrite grain may be due to higher chromium content at ferrite grain than austenite grain.

Table 1 Study on preparation of molecular calcium carbonate system NUMBER Consumption of Na2CO3（ml） Phenomenon 1 5.1 Clarification 2 5.2 Clarification 3 5.3 Muddy 4 5.4 Muddy and Precipitation We can see from table 1, when the turbidity appeared to join the 5.3ml Na2CO3 solution system, a Calcium Carbonate Granules generation system, the preparation system of image is shown in Figure 1, calcium carbonate particle characterization of the image shown in figure 2.
Fig. 1 Image preparation system Figure 2 CaCO3 particles We can see from Figure 2, the red circle indicates that the particles of micron Calcium Carbonate Granules system, the median grain diameter is 0.0990nm, that Calcium Carbonate Granules size is micrometer or smaller particles.
With the increase of polymer concentration, median grain diameter decreases system.
With the increase of surfactant concentration, median grain diameter did not change the system.
With the increase of the pH value, median grain diameter did not change the system.

Nitrogen is a grain refining element and rises the hardness substantially.
R: regular threefold core-rim type grain, I: inverse twofold core-rim-type grain.
It was claimed that because of reduction of the number of interfaces these solid-solution cermets should have better mechanical properties, which was not yet proven.
The number of journal papers published in the last years has increased drastically and cannot be overlooked easily.
As can be seen from Fig.11b average atomic mass particles formed rather large grains because of the lower nitrogen content and the absence of its grain-refining effect.

In this paper, the nature of steady state demixing of yttria-stabilized zirconia in an electric field is examined for the case of open system conditions (very fine grain material) wherein the defects are everywhere close to internal surfaces which allow the Schottky defect reaction to occur.
Here, qA(B) is the number of charges on A(B).
The former might be expected to correspond to single crystal material whilst the latter corresponds to material with a very small grain size.
Theoretical Development Let us introduce site fractions (with respect to the total number of sites) of yttrium ions, zirconium ions, cation vacancies, oxygen ions and anion vacancies as cY, cZ, cV, cO, cVo.
Schmalzried et al. [3] have determined that the condition that leads to steady state is: Ji - vci N = 0, i = Zr,Y (3) where N is the total number of lattice sites per unit volume.

On the other hand there are problems with the grain growth at higher temperatures.
The original more or less uniaxial grains changed into very asymmetrical elongated grains with the long axis in the extrusion direction.
There is not sufficient number of the independent crystallographic equivalent slip systems to fulfil the von Mises criterion.
Non basal slip and/or deformation twinning are needed for deformation of certain grain compatibly together with the neighbouring grains [4].
It is possible in small grained material at higher strain.

/s) (Fig.1 b) a lower number of short circuits is registered.
In this stratum polyhedral austenite grains can be found alongside with disordered (disoriented) dendrites.
The grain stratum is the most distinct in sample № 2 (Fig. 4 b).
In sample № 3 (Fig. 4 c) the polyhedral grain structure is also to be well-defined.
However, there are short and highly-branched dendrites in the grains.