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As the deformation rate decrease, the lamellar organization in the titanium alloy will convert into the equiaxed grains.
When the sample was compressed for 5.6mm, a few equiaxed grains occurred.
When the sample was compressed for 7mm, a large number of equiaxed grain occurred.
When the sample was compressed for 7mm, a large number of equiaxed grain occurred, this is because that the deformation of powder particles was so sufficient that distortion energy had been produced a great deal, which made dynamic recrystallization carry out completely.
Further compression up to 7mm, a large number of equiaxed grain occurred.

If the numbers of grain boundaries are too much, the corrosion of the alloys is severe.
Nd showed a significant grain refinement function on the alloys.
With the increment of Nd content, the fraction of the second phases became higher, the number of the grain boundary is increased. 2.
The result was directly related to the microstructure of alloys, which was attributed to the combined contributions of the better uniform microstructure, the lower fraction of second phases and the less number of grain boundary. 3.
Compared with the MZC2.0Nd alloy, the increases of both the fraction of second phases and the number of grain boundary were observed in the MZC3.0Nd alloy.

The finer-grained copper was able to outperform (by between 4- to 16-fold) its coarser-grained counterpart under severe test conditions, but no advantage was observed when conditions were milder.
At such fine grain sizes, the volume of the material influenced by proximity to a grain boundary becomes significant [1-3].
In the present study, elemental copper powder, with average as-received grain size of 156 nm, was mechanically milled for 10 hr, reducing the grain size to about 25 nm.
There is also a marked difference between the degree of oxidation observed on the finer-grained and coarser-grained copper: the oxide on the former is more extensive, while that on the latter is sparse and patchy.
The greater number of reactive grain boundaries in the finer-grained 63 nm copper promotes oxidation, and the rate of formation of the oxide layer.

By severe plastic deformation of metals, an ultra fine grain size can be obtained.
The specimens after ECAP showed a very fine grain size, a decrease of <100> // ND, and an increase of <111> // ND textures.
The as-deformed metals retained high dislocation densities, a large number of low angle sub-grain boundaries, and showed being in non-equilibrium configurations [7].
The grain of initial Al sheet exhibited an equi-axial, uniform, and coarse structure.
The grains were elongated, having an angle of 15 - 30 degrees to the ECAPed out direction.

The SEED process was employed, and the pouring temperature adjusted to prepare semi-solid slurries with different grain morphologies.
In this work, the six kinds of pouring temperatures from 630 °C to 705 °C were used to prepare slurry with different grain structures.
The entrapped air result from turbulent flow, so the number of the entrapped air can represent the flow stability of slurry.
The slurry microstructure of Tpour = 630 °C is close to globular, only at the edge region found small size dendritic grain.
The grain size increased as the pouring temperature rising, which is supported by the quantitative analysis presented in Fig. 3.

The two plate surfaces including the faying edges were thoroughly cleaned from and oxides and dirt using silicon carbide paper with grit number 800 in order to avoid their intrusion in the weld nugget while welding.
The reason to this softening is referred to the increase of weld nugget grain size.
The coarse grain size not only softens the structure but also increases its ductility.
Higher ratios lead to higher degree of deformation and consequently finer grain size.
Acknowledgment The authors would like express their sincere thanks to SABIC- Saudi Arabia for financing this work, grant number 427/30.

A large number of fine secondary-NiOss particles were separated from the CaOss crystal grains in CaO-NiO solid solution and improved the hydration resistance.
Once the sintered compacts are processed into grains of < 1 mm for the use to the nozzle as the raw material, the grains will be hydrated.
The microstructure of the sintered compacts is shown in Fig.9(a), which consists of white grains and a dark matrix.
EPMA analysis indicated that the white grains are a NiO rich solid solution (primary-NiOss) containing around 7 mol% of CaO.
A large number of fine particles (< 0.3 µm) were found to uniformly distribute in the matrix.

Austenite grain size about 1µm was reported.
These two phenomena are directly controlled by the number of nucleation sites.
Additionally, it was observed that coarse-grained IF steel (IF1) was deformed inhomogeneously while fine-grained specimens have been deformed smoothly.
Typical IF steel represents coarse-grained structure.
Weng (Ed.), Ultra-Fine Grained Steels.

Therefore, many research focused on the size effect in metla forming of mini parts and it can be characterized by volume grain size, surface grain size and grain size to thickness size effect [3].
Material and methods The spur gear specifications are shown in Table 1, In order to evaluate the effect of annealing treatment on grain size resulting in varying deformability of the commercial pure titanium (grade 2, CP2), a mini gear with an outside diameter (2*R0) of 9.2 mm, number of teeth (N = 8), and face width (h) of 5 mm, was proposed as shown in Fig. 1.
Specification of spur gear dies Parameters Value Number of teeth 8 Module 0.92 Pressure angle(˚) 20 Pitch diameter (mm) 7.36 Addendum circle (mm) 9.2 Dedendum circle (mm) 5.06 Face width (mm) 5 Modification coefficient 0 Fig. 1.
Fig. 3 (c) reveals that grain forms when AT is 700°C and the average α-phase grain size is 96.7µm.
Therefore, the average grain size for the specimen that contains β-phase grain is not calculated.

Neither the radial nor the thickness resonance parameters of discs (coupling factor and frequency number) significantly change up to 100 oC.
These conditions provide ceramics with a density of 91% and a grain size of 4.0±1.1 µm (equivalent diameter measured by quantitative image analysis: average and standard deviation of the ensemble of grains in an image).
As a matter of fact, analysis of the grain size distribution indicates that incipient abnormal grain growth already occurs at 1200 oC.
Denser ceramics with a similar grain size can be obtained by reducing the PbO partial pressure and increasing temperature.
The second ceramic material was sintered at 1250 oC with PMN-PT, and presents a density >95% and a grain size of 3.4 ±2.2 µm.