Search results

And the Al2O3 nanoparticles and Ni grains diameters in thin films are about 40nm and 80nm, respectively.
It is explained that Ni-Al2O3 films obtained by pulse current electrodepositing showed compacter surface and less grain size, while those obtained by direct current electrodepositing were rougher in surface and bigger in grain size.
According to the theories in electrodepositing, the stronger the cathode polarization is, the faster the rate of crystal nucleation, and the more the number of nucleuses.
Therefore, the film can be obtained with a compact surface and fine grains.
And the Al2O3 nanoparticles and Ni grains diameters were about 40nm and 80nm, respectively.

Substantially larger grains could be recognized for sintered samples with the addition of BaF2 (Fig. 3(B)) and CaF2 (D), indicative of the promotion of grain growth in the presence of these additives.
Liquid phase has been cited as a major causes of this kind of abnormal grain growth [11].
Activation energy for oxide ion conduction tended to increase as the number of cation vacancies decreased for the LSO samples with oxygen stoichiometry (No. < 1 > → < 4 > → < 5 >).
Ba3Al2F12 additive had similar effects on the densification and grain growth but a stepwise sintering (1400ºC/5 h → 1450ºC/5 h) brought about the inhibition of abnormal grain growth at 1450ºC.
On the contrary, the BaF2 addition positively assisted both the densification and grain growth.

In conclude, with the increase of filament number, the uniformity of temperature field improved a lot.
Fig.2 Influence of filament number on the temperature field of the substrate Fig.3 Influence of filament diameter on the temperature field of the substrate The influence of the distance between the hot-filament and the substrate hf on the temperature field of the substrate surface is shown as Fig.4, presumed that the hot-filament Tf＝2400℃, filament number n=12 hot-filament diameter df =0.06cm.
It can be seen from Fig8 that the grains of diamond film were arranged densely; the grain boundary was very clear, and the grain size was uniform.
The grain size at the center of the film was basically same as the grain size at the edge of the film.
(1) The substrate temperature increase along with the increase of filament number, hot-filament diameter, and with the decrease of the distance between the hot-filament and the substrate.

The XRD shows that a sample is primarily in both tetragonal and rhombohedral phases coexist and the amount of rhombohedral phase decreases that is due to the donor (Nb) dopant reduces the number of oxygen vacancies and leads to a lower amount of rhombohedral phase.
Above the limit, the excessive Cr ions segregate at grain boundary and inhibit the grain growth.
The grain size then increases at higher concentration of the doping.
Both of Nb and Cr impede the grain growth, which explains the decrease of the grains from 0-0.6 mol% Cr doping.
After that the grain size increases, which can be attributed to the more solubility of Nb (donor dopant) and Cr (acceptor dopant) in the system, resulting in the balancing of the excessive oxygen vacancies which leads to enhanced grain growth.

The slit was 0.1 mm and very small grains are imaged.
Bigger grains are seen as longer streaks with the streaklength corresponding to the grain diameter in scanning direction (transverse direction).
They consist of a large number (e.g. >1000) of sharp and narrow peaks (e.g.
For the discussion of the experimental data it is necessary to know more about the relationship between the number of input orientations and the number of agreements with the calculated values.
Figure 18 Relationship between random number N and correlation with the calculated values.

This wire tool with resinoid diamond grains (grains diameter about 20~40µm) is used to cut silicon ingots.
The abrasive diamond grain should be the same size as the SiC grain being used in free abrasive wire sawing.
In the manufacturing process, diamond grains are first stirred into SiC grains.
After selecting factors, their desired number of levels is determined.
The smaller grain size, the better kerf width.

The grain refinement theory.
For 125K ≤∆T≤195K, dendrites are regenerated, but the grain size is reduced (Figs.1c).
According to Karma’s model for dendrite fragmentation, the grain refinement of undercooled Ni-11%Si alloy was in good agreement with the experimental data, and the grain size was reduced with the increasing ΔT.
Karma, Model of grain refinement in solidification of undercooled melts, J.
Herlach, Physical mechanism of grain refinement in undercooled melt, Phys.

The scanning electron microscope (SEM) was used to observe the grain size.
The grain size was determined by averaging over the total number of grains in the SEM micrograph and found to be increased from 0.18 to 0.35 µm as the sintering temperature increased from 1200 to 1280 °C.
This is because larger-grained sample has lower concentration of grain boundaries [9].
Domain walls form harder when the grains are getting smaller.
For the PZT films, grain sizes increased with increasing Zr content.

Determination of the parent grain orientation.
When a sufficient number of variants are considered, there is a unique common potential parent orientation which is the searched parent orientation gp [1].
As a result, gp is obtained when the three following conditions are simultaneously met: 1- the variants are inherited from the same parent grain; 2- the number of variants is sufficient; 3- the OR (Δg0) is known.
Insufficient number of variants.
When the number of variants gathered is not sufficient (condition 2), the variants are equally related to several potential parent orientations.

A number of new technologies have been recently reported [3-5], but those new technologies, based on the control of pouring temperature or by the low temperature technique, control the solid morphology.
As the larger stirring power (i.e. 352W), there are a number of the fine grains with globular-like in the microstructure, as shown in Fig.3a.
As the stirring power reduces to 60W, there are a number of the coarse grains with rosette-like and no dendritic-like grains in the microstructure, as shown in Fig.3c.
The broken fragments from primary dendritic crystal grow up the new drifting grains at low temperature to realize drifting grain multiplication and to increase the number of the grains.
The process similar to equiaxed structure in the grains is taken place and the stirring effect makes the grains change into near globular-like [11].