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In addition, an improvement in mechanical properties of the castings fabricated by the FSD method is expected since there are few porosities and fine equiaxed grains in the castings.
The fine equiaxed grain structure may be formed by the following mechanism.
On the other hand, in the metal-mold casting, a columnar structure was observed in the side locations and a coarse equiaxed grain structure was observed in the center of the castings.
The sand-mold castings had a coarser equiaxed grain structure due to its small cooling rate.
The results indicate that the castings produced by the FSD method exhibit a superior tensile strength due to a fine equiaxed grain structure.

This amplifies the local flow behavior, as it is dominated by the orientation of the individual grain and not averaged by the influence of multiple grains like in polycrystals.
A wire structure, which has only one grain across the diameter, but more than one grain along the length, is called bamboo-structure, as the shape after plastic deformation looks like a bamboo rod.
This is because the area around the grain boundaries deforms less than the area between the grain boundaries, which ends up in thicker sections at the grain boundaries and thinner ones in between.
This results in Stribeck numbers of 1.9 mm5/Ns² to 165 mm5/Ns².
It can be seen that the ranges of the Stribeck numbers for size20 and size100 show a wide overlap.

Fig. 3a shows an Image Quality (IQ) map overlaid with high angle and low angle grain boundaries.
An improvement in the phase separation is obtained by using Grain Average Misorientation (GAM) or Grain Average IQ (GAIQ) maps.
The GAIQ criterion with the same grain boundary tolerance of 5 deg gives the same result (fig 3d), but both GAM and GAIQ with a grain tolerance of 0.5 deg give a well defined separation of ferrite and martensite.
IQ map and grain boundaries; b.
Acknowledgements This research was carried out under the project number K41.5.09366 Texture control in single en dual phase steels in the framework of the KWR knowledge workers scheme of SenterNovem (Ministry of Economic Affairs, The Netherlands) and the Materials Innovation Institute M2i (www.m2i.nl).

In order to improve thermal and physical properties of sialons, number of different additive alone or in combination [10-12], and heat treatment process [13] have been used to synthesis of silicone based ceramics.
The formation of elongated grains was demonstrated that the elongated grains give better mechanical properties [19].
The growth of the α-sialon grains depend on the formation of the liquid phase during the sintering.
It can be seen from the micrograph that there are good grain enlargement and micro porosities in the compact.
The growth of the α-sialon grains also depended on the amount, the composition of the liquid and sintering temperatures.

Prior to testing, the specimens were numbered and polished with SiC papers with up to 1200 grit to meet the requirements of the corrosion tests.
Dynamic recrystallization took place at the grain boundary and extended into the grain when extruding at 250℃.
Meanwhile, visible large grain on both sides of fine grain and original grain far distant were still exist [4].The microstructure changed during the extrusion process, which may due to the change of dislocation density and dislocation rearrangement.
New grain would formed once the dynamic recrystallization happened.
Circular corrosion pitting formed because fine grain was easier to corrode than bigger grain.

Combined additions of Sc and Zr to Al alloys are more effective for improving their recrystallization resistance and service performance due to the precipitation of high number density of nano-sized, coherent Al3(Sc, Zr) particles with bilayer structure [2].
The microstructure of the base alloy consists mainly of large-sized, elongated recrystallized grains.
In general, the surface of fine grained Al or Al alloy with high grain boundary density has the ability to passivate more readily than the coarse grained one, which inhibit further attack [16].
The discontinuously distributed grain boundary precipitates can cut off corrosion channel along grain boundaries and prevent local anodic reaction of grain boundaries region.
Moreover, the local corrosion attack needs to propagate longer grain boundary path for attacking the same corrosion depth for 0.06 wt% Sc-bearing alloy due to grain refinement.

The substitution of Pr for La gives rise to a visible grain refinement of the as-cast alloys instead of changing the phase structure of the alloys.
It can be seen that the substitution of Pr for La brings to the notable refinement of the grains of the as-cast alloys.
Fig.4 describes the evolution of the capacity retaining rates (Rn) of the as-cast and spun alloys with the cycle number.
The capacity retaining rates (Rn) of the as-cast and spun (20 m/s) alloys as a function of the cycle number are depicted in Fig.6.
Both the substitution of Pr for La and the melt spinning markedly enhances the cycle stability of the alloys, which is accredited to the refinement of the grains caused by such substitution and melt spinning due to the fact that the grain refining notable enhances the strength and toughness of the alloy, increasing the anti-pulverization ability of the alloy.

The P/M process in the Al-Mg-Zr alloys in study leading to fine grain structure after the thermal treatment.
The influence of the particles depends on a number of factors and on whether the particles are present during deformation or whether they form during the subsequent anneal before recrystallization occurs [5- 8].
A comparison of microstructures (TEM micrographs) relating the conventional processing with the discussed Al-Mg alloys in this work, is shown in the figure 2 of the 6063 aluminum alloy sample: a) Cold worked (20% reduced in area.), grains with crystalline defects; b) Cold worked (50% reduced in area.), intense dislocations tangles inside the grains; c) elongated grains after cold worked with 90% reduced in area, and d) Cold worked (90% reduced in area) and heat treated at 735K for 60 s, recrystallization process proceeds, presence of disperse precipitates and some dislocation tangles inside grains.
That process in the Al-Mg-Zr alloys in study shows more notable, leading to fine grain structure after the thermal treatment.
W.: Recrystallization, Grain Growth and Textures, Ed.

As rSr = 0.144 nm (coordination number is 12), rBa = 0.131 nm (coordination number is 12), rTi = 0.061 nm (coordination number is 6), rO = 0.140 nm (coordination number is 6), and rBi=0.117 nm (coordination number is 8), the tBi =0.904, it is located in the allowance factor scope, and the structure is stable.
From the Fig.2 we can see the wave-number 2935cm-1 indicates of C-H vibration absorbing peak.
The decreased dielectric loss is also related with the grain size.
The Bi3+ doping produced influence on the grain size and decreases the grain size.
It can be found that the grains size is about 30-100 nm from the Fig.5 (b).

Figure 2 illustrates projection of tilted symmetric grain boundary structure Σ13.
Projection of the structure of tilted symmetric grain boundary Σ13 on to plane (001) upon relaxation; Ф – grain boundary misorientation angle Discussion of computation results The sample reaction force as a function of indenter penetration depth is presented in Fig. 3.
Note that in the case of crystallite having grain boundary, the onset of plastic deformation is observed for lower depth of indenter penetration.
A satisfactory match is observed between the former curves and the curves describing variation in the number of atoms involved in the local structural changes.
Note that the grain boundary hampers the local structural changes from encompassing the neighboring grain (see Fig. 4 d).