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By addition of colloidal silica in copper electrolytic bath and Au pre-coating on substrate, the grains of deposits became fined and uniform and the number of grains were increased.
When plating over-voltage is low, the size of grains is large and the number of nuclei is a little.
As silica was dispersed, however, grains were refined, the grain size of copper significantly decreased and the number of grains and the thickness of Au pre-coating increased.
As Au pre-coating increased the number of nucleation sites, the nucleation became faster than that of the grain growth, which is considered to the role of prohibiting grains growth by refining and increasing the number of grains.
Fig. 4 X-ray diffraction patterns of electrodeposited copper obtained with different amounts of colloidal silica added and/or with different amounts of Au pre-coating thickness Summary The grains of copper electrodeposited film refined, uniformly grow and increased the number of grains by Silica dispersion and Au pre-coating.

In the water-quenched samples, equi-axed fine-grained microstructure with grain size under 2.1μm was attained and maintained throughout the hot rolling process.
Therefore, in the present study, control conditions in hot rolling such as cooling way from homogenization temperature, cooling way after a rolling pass, total number of passes, etc. have been investigated in a Zn-Al alloy to obtain fine-grained microstructures by rolling processes.
Degree of grain refinement was evaluated with average grain size, L＝1.75d [6], where d is the linear intercept length and averaged in two directions for the three sections.
A minimum grain size of 1.7 μm was observed at 6 passes in the 7mm thick sheet.
Fig.2 SEM micrographs in L-LT section of the samples hot-rolled under condition (1) from 20mm to different thickness (with different number of passes).

The strongly grain size dependent work hardening behaviour at room temperature is shown to arise from both the grain size dependence of the dislocation storage as well as the grain size dependence of twinning.
The Consid`ere criterion is also shown (dashed line), the numbers refer to the first column in Table 2.
In the case of the fine grained material, twins were observed at higher strains but only in a fraction of the grains.
These numbers appear to be in good qualitative agreement with the TEM observations described above.
The predictions for the intermediate grain sizes is less good than at the coarse and fine grain limits.

The number of intermittent baseline cycles between consecutive overloads was varied (n=100 and n=10.000).
The influences of grain dimensions and number of intermittent baseline cycles on these effects were studied in the test program.
The overload tests were carried out with the two different numbers of intermittent baseline cycles n=100 and n=10.000.
Depending on the grain dimensions and the number of intermittent baseline cycles between the consecutive overloads, acceleration or retardation of crack propagation occurred compared to constant amplitude loading (Fig 2a and 2b).
The impact on crack propagation rate depends on the grain dimension, the slip distribution at constant amplitude, and number of intermittent baseline cycles between the consecutive overloads.

If that is the case, defragmentation of grains can occur (see Figure 1, (d) - (e)) to form fine recrystallized grains.
Description Parameter Strain ϕ Grain diameter d Grain diameter d0 Recrystallized grain diameter drex Grain boundary energy γgb Recrystallized grain fraction X Driving force (stored energy) PD Retarding force (Zener Drag) PZ, PZ,sub Number of nucleii N Change in number of nucleii ∆N Experimental Procedure Light Metals Technologies Ranshofen (LKR) owns a semi-industrial extrusion press (type Müller Engineering NEHP 1500.01), used to perform the experiments.
Fig. 2: Histogram of dispersoid number density per volume for the homogenized sample.
grains.
One of the input parameters for the grain growth model was therefore the average grain size of the cast billet.

This is the natural boundary condition when a fixed number of particles diffuse, each for some time t.
A random number is generated to determine the outcome.
The lattice model with a variable lattice spacing for addressing the problem of diffusion from an instantaneous tracer source at y = 0 in the presence of a grain boundary slab (normal to the surface) ; (a) shows a small mesh size in the vicinity of the grain boundary, (b) shows a large mesh size for the grains except in the immediate vicinity of the grain boundary slab.
(Care must be taken for problems with a changing number of particles introduced into the system so that the 'clock' is suitably rescaled.)
(In the parlance of grain boundary diffusion, this would be the Hart Equation.)

Grain Refinement by High Temperature Plane-Strain Compression of Fe-2%Si Steel P.
After 75% reduction the equi-axed grains exhibited an average size of 10 µm which represents a strong grain refinement with respect to the initial size of 80 µm prior to PSC.
At isolated sites in this lamellar band structure a number of equi-axed grains can be observed.
Because these grains are associated with a sharper Kikuchi band contrast it may be readily assumed that they represent highly recovered or even recrystallised grains.
Average misorientation of recrystallised grains vs. temperature.

During hot compression deformation of 1235 aluminum alloy, slidings occur sooner or later and the number is different for the difference of grain orientation, and so the distribution of grain orientation as well.
The time of occurrence and the number of slips differ for the difference of polycrystalline grain orientation during deformation.
From the charts, there are a large number of low-angle boundaries and high-angle boundaries with wealth distribution information in 1235 aluminum alloy after hot compression deformation.
At the strain rate for 50s-1, there are a larger number of small low-angle boundaries in grains (the percentage of angle less than 3° is 41.1%).
At strain rate for 0.1s-1, the major textures are Goss (G) textures, Brass (B) textures, Rotated cube textures, including a small number of R textures and cubic textures.

Under tensile conditions, thin specimen exhibit softer mechanical properties when the number of grains across thickness is lower than a critical number and this modification appears above a critical strain level.
Several previous studies reported a softening of the stress when the number of grains across the thickness, characterized by the ratio between the thickness (t) and the grain size (d), is reduced.
A sample is defined as multicrystalline when its number of grains across the thickness is lower than (t/d)c.
Assuming the normality of the plastic flow, the strain path is also modified by the number of grains across the thickness.
This thickness reduction is plotted versus the number of grains across the thickness for each complex loading.

With increase in the number of pass, the percentage of elongation increases slightly.
Hardness vs Number of passes Fig. 7.
Elongation % vs Number of passes Fig. 8.
Tensile strength vs Number of passes · The microstructure of the extruded specimen and ECAP specimen is compared.
· Tensile strength and hardness increases with the increase in limited number of passes