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The surface morphology induced by laser annealing of a-Si thin films is found dependent upon the laser fluence and shot number.
The laser energy was found to be distributed non-uniformly resulting in the microstructure with the mixture of larger grains and smaller grains scattered on the film.
Shot number effect.
It can be seen from Fig. 3a that as a-Si films laser irradiated using the repetition rate of 10 Hz and shot number of 50 shots at the fluence of 190 mJ/cm 2 is noted to result in a larger grains by lateral crystallization process due to the increase of the melting duration and the reduction of the vertical solidification velocity.
(3)The increase of shot number to 50-100 shots, at the repetition rate of 10Hz and the laser fluence of 190 mJ/cm 2, is beneficial in producing larger SLG grains.

Formation of a multiphase state, represented by grains of α-iron and inclusions of carbide phases based on iron, chromium, and niobium, is revealed.
The total number of counterbody rotations was 5000.
Namely, mass formation of nanoscale particles of carbide phases located in the volume and along boundaries of α-iron grains.
Formation of a multiphase state, represented by grains of α-iron and inclusions of carbide phases based on iron, chromium, and niobium, is revealed.
It is shown that the main carbide phase is the iron-based carbide, located in the form of extended layers separating grains of α-iron.

There were a lot of discontinuous grain boundaries in the as-extruded alloy GH720.
Uniform, fine and equiaxial grains were obtained during heat treatment process because the grain boundaries of GH720 were pinned by γ ' phases and growth of recrystallized grain was limited effectively.
A few small dynamically recrystallized grains had been developed along the grain boundaries in extrusion process.
A large number of dislocations got tangled up each other and the cellular substructures were formed by the dislocations glide and climb in extrusion process of GH720.
The recrystallized grains grew by grain boundary migration.

However, all recrystallized grains are about the same size, implying that these cube grains do not have a growth advantage compared with their neighbours.
They appear on either horizontal or vertical grain boundaries.
Because of the large grain size of the starting material and limited number of grain boundaries after heavy deformation over a very large area, we were not able to quantify statistically the presence of intergranular cube fragments.
Grains are elongated, growing into the two neighbouring grains predominantly along the RD direction.
Some near-cube grains were formed on the boundary between the two grains during the deformation.

Rated load on counterbody was 10 N; finite number of sample rotation - 5000.
Namely, it contains separately located point reflections belonging to α-phase (solid on the base of bcc lattice of iron) and a large number of thin diffraction rings belonging, most likely, to nano-dimensional particles of carbide and oxycarbide phases.
First, the lamellar pearlite grains in which the ferrite grains are divided to disoriented areas are revealed.
The similar structure forms in the grains of ferrite-carbide mixture as well.
Second, the pearlite grains and grains of ferrite-carbide mixture with partial or complete dissolution of cementite plates are determined.

Martorano et al. [4] observed columnar grains oriented approximately parallel to the cylindrical ingot axis at lower mold velocity and a large refining effect at lower velocities.
However, it is still lack of a method for precise control of dislocation density, growth orientations, and grain boundary (GB) type of UMG-Si ingot.
The dislocation density in the central part was less than that at the bottom and top because of slight supercooling, larger grain sizes, and complete growth of columnar crystals.
Recent studies showed that the presence of a large number of carbon sources in the silicon melt could promote formation of the ∑3 boundary.
Fig. 2 Distribution profiles of dislocation Fig. 3 Distribution of grain boundary type density along the cross section of the ingot in the middle part of the UMG-Si from bottom to top Conclusions The dislocation density in the ingots increased with the withdrawal rate increase.

As shown in Fig. 4(a), from the perspective of the metallographic structure, the base stock of the Hastelloy C-276 cylindrical part prior to the power spinning process is made of single-phase austenites (grain fineness number: 4-5) including a considerable amount of twins.
Fig. 4(c) shows the metallographic structure of the annealed base stock with a thickness reduction rate of 79%, which is similar to the case prior to power spinning in its grain fineness number and grain shape.
It can be seen that while the thickness reduction rate increases, the grains in the base stock are refined to a greater extent and arranged more neatly and more densely, leading to higher strength and lower plasticity.
Both the number and the size of corrosion pits increase as the thickness reduction rate grows, and its corrosion resistance after the power spinning process as well as the internal stress-relieving annealing treatment is obviously higher that that of raw materials.
Conclusions The impacts of the power spinning process on the cylindrical part can be summarized as follows: The firs, the grains in the base stock and the weld zones of the Hastelloy C-276 cylindrical part are refined during the power spinning process at room temperature, causing higher grain directivity and strength and lower plasticity.

The area fraction of the � phase is increased as the pass number increases from 1 to 2 passes and the individual grains become more equiaxed.
Figure 3 plots the elongation to failure against the number of ECAP passes for samples processed with dies having channel angles of �=90 o and 135 o.
For both dies, the elongation to failure increases with an increasing number of passes.
The area fraction of the � phase was increased as the pass number increased and the individual grains became more equiaxed.
(5) Upset testing showed that the maximum formability increased as the number of ECAP passes increased.

of atom) Bond angle variance : s2=Smi=1(fi-f0)2/(m-1) (fi: Bond angle, f0: Bond angle of regular body, m: number of face) Fig. 5.
The same analysis was performed to separate grain and grain boundary conductivities.
The grain boundary conductivity seems to be directly related to Mg carrier concentration in the vicinity of grain boundary.
Three to four resistance components attributed to grain, grain boundary and electrode interface were successfully separated.
For undoped sample, grain and grain boundary conductivities were 1.7 x 10-3 and 1.9 x 10-5 S/cm at 600oC, respectively.

The results show that the corrosion rate of the ultrafine-grained alloy decreases, in comparison with the coarse-grained alloy.
The number of ECAP passes is 4.
After four passes, remarkable grain refinement occurs by repeated shear deformation, and the grains of the alloy were refined to submicron level after four passes.
In that way, grain size is an important factor for improving corrosion resistance.
The pits on the coarse-grained sample surface (0P) are much larger and darker than those of the ultrafine-grained sample (4P).