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The average grain size of the powders obtained after hydrothermal treatment at 160ºC for 9h was about 30nm with cubic structure.
A number of important physical, chemical, mechanical or mixed procedures have been proposed, among which the hydrothermal method has been found to be very promising for the preparation of well optimized and non-agglomerated powders [5-10].
The grain size of the powders was estimated using the Scherer's equation: θβλ cos/kd = (3) where d is the grain size, k sharp factor(0.9), λ the wave length of X-ray (0.15406nm), β the full width at half maximum(FWHM), and θ the Bragg angle.
average grain size was about 30nm with uniform distribution, which was in good agreement with the grain size determined from XRD.
Acknowledgements This work was partly financially supported by National Hi-Tech Research and Development Program of the People's Republic of China (Project Number: 2004AA32G090 ).

At 400oC grain growth took place yielding a bimodal microstructure with mean grain size of 9 microns.
The grain size was reduced to 1.5 um and 9 µm respectively.
At 400oC the distribution is bimodal and grain boundaries are decorated with small grains indicating the process is controlled by dynamic recrystallization.
Smaller grains decorate the interface between larger grains.
These larger grains have a recovered inner structure and collars of small grains at the high angle interfaces.

The strength of Cu-Ag alloys is determined by a number of strengthening mechanisms, which to a certain extend influence each other.
Work hardening originates from the cold work, that is applied in order to prepare the wire in its final dimension, and thus takes into account both, the increasing number of dislocations and the decreasing grain size.
Perpendicular to the drawing direction, i.e. the shorter length scale of the grains, a mean grain size in the order of 100 nm is estimated by TEM analyses.
From Fig. 5b primary recrystallised grains can be seen, which have a mean grain size right below 100 nm.
However even coarsened grains are observed after annealing the sample at this temperature.

The effective strain gradient increases with the number of compression.
Introduction The reduction of average grain size to an ultrafine grain scale represents a traditional way of improving mechanical properties of polycrystalline metals and alloys.
The number of initial tetrahedral elements was 30000.
Moreover, the strain gradient increases with the number of CCDC.
The strain gradient increases with the number of CCDC by two routes

Misorientation Effects on Grain Boundary Grooving of Ni by Liquid Ag P.
On the contrary, GB energies vary in a very wide range depending on grains misorientation and plane position.
Grain size about 100 - 200 µm was obtained.
Randle: The Measurement of Grain Boundary Geometry (IOP Publishing, UK 1993)
Nevertheless, the study of a large range of GBs geometry required the use of a great number of different bicrystals.

The loading chips are mechanically removed with abrasive grains and bonding materials from the wheel surface by dressing, and abrasive grains under the previous wheel surface show up.
They are increase with increasing the number of treatment � till the four or five times.
Even if just once wheel treatment is carried out, the abrasive grains can project about one third of grain size.
The number of grinding, in which grinding current is higher than the steady current, increases with increasing the number of treatment �.
The surface roughness decreases with increasing the number of wheel treatment at steady grinding process.

Inversely, at lower sintering temperature, such as 900ºC, the sample exhibited smaller grain size, which contributed to a higher amount of amorphous grain boundary phase compared to that in the samples with larger grain size.
The higher number of contact points between the particles activates the transport of matter, leading to the higher number of necks between the particles, enhancing the diffusion and evaporation-condensation of the matter on surfaces with consequent bulk densification.
The understanding of the development of the morphological features i.e. grain, grain boundaries and pores is important because a high amount of porosity and larger number of grain boundaries would be effective pinning centres to domain wall movements, hence increasing the demagnetizing effect in the sample which results in decreases of magnetization.
Increase in the density and grain size and the decrease in porosity with sintering temperature would influenced the permeability where large grains diminish the number of grain boundaries, therefore results in reduced the hindrance of the domain wall motion.
Besides that, the fraction of grains that are occupied with domain walls increases in the larger grain thus increases the eddy current and hysteresis losses.

A special etching (CuSO4 + HCl) was also used to distinguish the grain structure.
The grain refining tests were performed on only one cutting temperature (590°C).
This is because a large number of nuclei are generated at low pouring temperatures, while at higher pouring temperatures it is impossible to produce a number of nuclei and the nucleation takes place during the first stage of the SEED process [6-7].
It seems that at higher pouring temperatures the addition of TiB2 does refine grain size, but this grain refining is not translated into a noticeable reduction of the α-Al particle size.
• The addition of TiB2 indeed reduces the grain size at all pouring temperatures.

Severe plastic deformation (SPD) is employed to produce Ultrafine Grained (UFG) structures.
Titanium sponge showed decreased grain size and porosity with increasing backpressure.
Over a decade, a large number of processes are being developed to reduce the cost and increase its applications [2].
On the other hand, the sample consolidated with 150 MPa back pressure showed a large number of small grains when compared to the sample consolidated by 100 MPa.
Horita, Using equal-channel angular pressing for refining grain size, J.

The grain size was 1-4µm.
When the substrate temperature was 600°C, the sheet had sharp irregular polyhedral grain, and when the substrate temperature was 700°C the sheet had quite regular grains.
The grains are with sharp irregular polyhedral shape.
As the number of turns of the substrate is 12 round/min, the upward vertical acceleration introduced by bonding force or adsorption affinity is calculated to be 8.5m/s-2.
The grain size is 1-4µm.