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According to the experimental results, the solidification structure of hypereutectic high chromium cast iron was modified from large grains to finer grains with equiaxed crystals, by allowing the ECP to act on liquid.
According to the experimental results, the solidification structure of hypereutectic high chromium cast iron can be modified from coarse long rod-shaped large grains to finer grains with equiaxed crystals.
The number of times Lorenz force regularly repeated increasing with increasing frequency, so from the Fig. 3(b) we can see the average diameter of primary grain gradually decreased with increasing of pulse frequency, effects of the pulse width the same as the effect of pulse frequency.
The liquid-solid interface is unstable and the grains will grow anisotropically in its perferred crystallographic orientation, leading to get a large number of rod-shaped primary carbides grain, because Liquid conductivity greater than the Primary grain, the current flow around the primary grain, which leading to increased current density of the solid-liquid interface, so the liquid-solid interface is table and grains grow spherically.
Different conductivity of liquid and primary grain, which leading to increased current density of the solid-liquid interface, so the liquid-solid interface is table and grains grow spherically. 4. equivalent diameter of primary carbides was decreased initially and then coarsening as the increasing of electric voltage, the average diameter of primary grain decreased with increasing of pulse frequency and pulse width in this experiment.

The effect of the loading conditions on the number of cycles to crack initiation is evidenced using a ∆εt-Ni plot.
The majority of the cracks are smaller the average grain size.
In "small SCV slip systems", the effective grain size is much smaller than the actual grain size.
Since the number of PSB remained exactly the same in all the simulated cases, this means that slip irreversibility increase takes place at the scale of individual PSBs.
CONCLUSIONS The number of cycle to initiation of large cracks (50-150µm) in thermal fatigue is 4-5 times faster than in conventional fatigue, for a fixed ∆εt,eq.

After the heat treatments, both AC and FC samples were processed by HPT at room temperature with a pressure of 6.0 GPa and a rotational speed of 1 rpm to total numbers of turns, N, of 1 and 10.
AC and FC samples have similar grain sizes in the range of 40 - 50 nm.
This grain size is smaller than the grain size of 110 nm obtained after 10 turns of HPT processing with an initial microstructure of equiaxed a phase + 52% lamellar [11-12].
Significant grain refinement, with grain sizes of 40 -50 nm, was obtained after HPT processing to 10 turns in both the air cooling and furnace cooling samples.
Langdon, Twenty-five years of ultrafine-grained materials: Achieving exceptional properties through grain refinement, Acta Mater. 61 (2013) 7035-7059

And the number of {111} twinning is far less than the other two types of twinning .
In order to describe the twinning number of different deformed structures quantitatively, the ratio of grain area with twinning and microscopic orientation image area is calculated and defined as twinning fraction.
The twinning grains in Fig. 4(a) and untwinning grains in Fig. 4(b) and (c) are marked by black lines.
Additionally, a number of parallel twinnings are existed in grains during the deformation process which means that more grains participate in the dynamic deformation through twinning behavior.
The number of the three types of twinning is 66, 11 and 39 respectively.

Liquid Gallium Penetration along Grain Boundaries in pure Al and Al - Based Alloys.
It was shown that crack-like channels filled by liquid Ga were formed along all grain boundaries.
In spite of number of papers published during the last years the mechanism of this phenomena is unclear.
Fig.1 Typical grain size structure of recrystallized samples.
Here, it was taken into account that effective Ga atom radii in Al lattice is more than for Ga atom in Ga lattice, because of the change of coordination number [14].

For efficient production of ultra-fine grain structure in the alloys with γ'- phase via SPD, it is necessary to have a large number of incoherent γ/γ' boundaries prior to deformation.
Annealing twins were present in some grains.
Recrystallized grains of submicron sizes were revealed near these areas, as well as in the original grain boundaries.
A lesser number of passes (by a factor of two) was required to generate refined structure in Allvac 718Plus than in Alloy 718.
These factors narrowed the MF temperature range and, correspondingly, decrease the number of passes needed to generate structures with the same refined grain sizes.

The microstructure of this ceramic material is constituted by large elongated β-Si3N4 grains with high aspect ratio embedded into a matrix of smaller grain size.
The plane A is constituted by numerous large elongated grains, promoted by the seeding, embedded into a Si3N4 matrix of smaller grain size (Fig. 1a).
Those elongated grains are mostly oriented with their lengths parallel to the extruding axis.
a 20 µm b 20 µm intensities of those peaks, (200):(002), can give an estimation of the degree of texture of the material, comparing it to the reference value calculated from the β-Si3N4 diffraction card (pattern number 33-1160) that is 6.7.
While the ratio for the surface A is 10.4, which indicates a higher number of elongated grains than in a standard Si3N4 material, the value calculated for sample C is one order of magnitude lower (ratio of 1.3).

With the increasing of original Cr3C2 content, the number and size of arborescent crystal increased obviously.
With the increasing of original Cr3C2 content, the number and size of arborescent crystal increase obviously.
On the surface of FGM, micro-score, deciduous and pulling-of TiC ceramic grains are observed, which is showing grain abrasion and plough ditch have happened.
Their FGM substrate is micro-cutted by deciduous TiC grain.
With the increasing of original Cr3C2 content, the number and size of arborescent crystal increased obviously.

This is because the formation of grain is the process of nucleation and growth, during which a large number of intensive microcrystalline grain region are formed.
Furthermore, large amounts of impurities and grain boundaries in the intensive microcrystalline regions inevitably cause a large number of dislocations.
Hidalgo P and his coworkers pointed out that the metal impurities near grain boundary spread to the grain boundary under heat treatment at a certain temperature.
This means that the grain boundary has the ability to adsorb and precipitate metal impurities, which is the so-called “grain boundary gettering” [7].
The concentrations of a large number of metal impurities could significantly reduce the minority carrier lifetime the phosphorus gettering silicon wafer.

Using sets of SEM images for each processing condition, an image measurement software was utilized to count more than 300 grains in each sample and then calculate the average grain size and the grain size distribution.
The grain size distributions show that the area fractions of the larger grains with sizes >5 μm is reduced to zero after 1 pass of ECAP and further grain refinement occurs between 1 and 8 passes.
With an increase in the number of ECAP passes, there is a significant decrease in flow stress and increase in ductility as shown in Fig. 2 (b), (c), and (d).
Meanwhile, the dimple numbers and dimensions are decreased with increasing numbers of ECAP passes.
Micro-tensile testing at a high temperature shows that the ductility of the AZ31 alloy can be improved significantly with increasing numbers of ECAP passes. 3.