Search results

The molecules number of per unit cell is four, the cation sublattice is face-centered cubic structure, anionic sublattice is composed of simple cubic structure.
Other materials with this structure include a number of materials used as nuclear fuel, i.e.
Scanning electron microscopy (SEM, Hitachi,TM3000) was performed to characterize the surface morphology and grain size of the power.
We can see that the grain are all hexagon, whose diameter is about 80um-180um, the size of the grains of the different powder have a little changes, first of all, the grain size of the a samples is the littlest in all the these sample, these is because the kind of powder is also littler than the other kind of powder.
Fig.4d is the surface of sample c soaked in 90°C for 5h ,we can see that the surface of the sample is damaged , the size of grain become thin, and the strength of boundary decreases .Which means the samples react which water at 90 °C, the concrete analysis will be given in the later discussion.

Austenitic lattice has a higher tendency to warp due to large number of slip systems.
Autors [4] indicates that for steel XCr17Ni7MoTiN, resizing a layer of plastic deformation is related mainly to the material structure and properties of austenitic grain size.
Figure 1 Plastic deformation of the surface, local plastic deformation in austenitic grain-hardening surface, zone of hole E To plastic deformation occurs under the surface finish and the local austenite grains.
At the same time claim autor2 confirmed that this is true for smaller austenite grains (~to 60 mm).
Acknowledgement The authors would like to thank in words the VEGA grant agency for supporting research work and co-financing the projects number #1/0048/10.

Among all the factors mentioned above, the chemical composition, cooling conditions, and austenite grain size capture the most essential features of a weld metal.
The microstructure needs to be evaluated for its phase composition, grain size, structure & shape as well as any evidence of microsegregation and other defects.
It has been well established that fine and equiaxed grains improve toughness, ductility and fatigue life of weld metal and reduce solidification cracking [2,3].
The different micro structural zones in heat affected region surrounding the weld can have grain coarsened zone, fine grain zone and partially transformed zone.
Fig. 1: Advanced Submerged Arc Welding setup Experiment The experiments were conducted according to the random run suggested by two-level half-fractional factorial design of eight trials to investigate the effects of a number of parameters on the required response [6].

Optimal extrusion parameters The mean-square deviation of effective stress was defined as: (1) Where N was the number of different effective stress; was the value of effective stress; was the average of effective stress [9].
After the first extrusion, there was a coarse and uneven distribution of a-Mg grains, together with a relatively uniform distribution of fine particles (~35 nm) within the a-Mg, Fig. 6 (b).
After the second extrusion, there was a significant reduction of a-Mg grain size and an obvious decrease in the particles size (~25 nm), Fig. 6(c).
Although the overall grain size in the alloy under the extrusion parameter No. 7 (Fig. 6(c)) was coarser than that of parameter No. 5 (Fig. 6(d)), the size distribution of the a-Mg grains was more uniform.
Microstructure analysis of the fan-shaped extrusion bars processed with the optimal extrusion parameters shows it has a more uniform size distribution of the a-Mg grains, which can significantly decrease the amount of defects in the products and improve the productivity.

The bulk and grain boundary contribution with frequency has been studied using Nyquist plots.
The dielectric properties depend upon several factors including the method of preparation, chemical composition, grain structure/size, the amount and type of the additives [3-5].
The impedance analysis allows separation of several contributions of total impedance, arising from the bulk conductance and interfacial phenomenon viz. grain, grain boundary and other electrode interface effects [6, 9].
It depicts the orthorhombic perovskite structure, with all the peaks matched with ICDD card number 01-089-7833.
One complete semicircle contributes to the grain part and another incomplete semicircle represents grain boundary contribution.

Formability is improved in fine-grained materials, especially at elevated temperatures, which is related to diffusion-controlled deformation mechanisms and grain boundary sliding.
In addition, superplastic materials must fulfill certain material-technical prerequisites [5]: Isotropic material structure, globular grains and a fine-grained microstructure (grain diameter < 10 μm).
The interpolation size describes the maximum number of adjacent facets that can be interpolated.
For example, the grains can slide well against each other in the uniaxial tension region.
Grain boundary sliding now likely also contributes to this type of cavity formation.

Dystectic TiN can be used as crystallization core, thus promote fine grain size and increase the ductility.
Acicular ferrite is located in the crystal grain of original austenite, and AF is fine connected lath-shaped matter.
AF can restrain crack propagation effectively, decrease grain size, and improve the ductility.
The attrib wattle bainite of sample 2 is bigger, long, thin, and straight, which almost runs through the whole original γ grain, and Bu appears.
Samples 1, 2 and 4 were welded under high current resulted in large molten pool and slow cooling velocity and large number of mesophilic microstructure and M-A component generated while freezing.

Alloying element Ti was added in the ODS steels in order to decrease the size of the oxide particles and increase their number density in the metal matrix.
Grain morphologies of the fabricated ODS ferritic steels were observed by field emission scanning electron microscopy (FE-SEM).
The grain morphologies of Al-free and Al-added ODS steels with 18%Cr substantially consist of the bamboo-like grain structure parallel to the extruded direction, which was depicted in Fig. 3 of Ref. [5].
The mean grain diameters of 18Cr-ODS steel and 18Cr5Al-ODS steel measured in a plane perpendicular to the extrusion axes are 0.91 and 1.58 μm, respectively.
On the contrary, their average grains measured in a plane parallel to the extrusion axes are 3.57 and 2.43 μm for Al-free and Al-added steels, respectively.

Resistive Mechanisms in Aluminum Chemical impurities; crystal imperfections such as vacancies, dislocations, grain boundaries, etc.
These values have been gathered from a number of sources, the reader is referred to two excellent reviews by F.R.
Nonetheless, the numbers given in Table 1 do provide an order of magnitude value that can be used to evaluate the different mechanisms.
Quality of Analysis Using the coefficients given in Table 1, the resistivity contribution from dislocations in a heavily cold worked metal (i.e. a dislocation density of 10 15 m -2) can be calculated to be 0.20 nΩm while the grain boundary contribution in an aluminum with equiaxed grain size of 30 µm is 0.02 nΩm (a grain boundary area per unit volume of 2 x 105 m -1).
The results can then be used to direct other measurements such as electron microscopy studies and reduce the number of observations necessary.

However, the TiB particulate size increased somewhat, and the number of nano-sized particulates decreased.
Some polygonal α2 (Ti3Al, D019) precipitates were also present, mainly at the prior B2 grain boundaries.
The average diameter of the prior B2 grains was ca. 100 µm.
The prior B2 grain size was inferred to be very small (ca. 5 µm) because of the TiB particulates' narrow spacing.
Figure 1 shows that the number of nano-sized particulates decreased in the GL composite.