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Mabuchi et al [3] reported that fine-grain Mg alloy with the grain size of 1 µm could be obtained by ECAE, which suggested that ECAE was a valuable method to refine the grain size of Mg alloy.
(1) Where N was the pass number, so the strain of each pass was 1.15.
The ECAE processing refined the grain size effectively, and ultra-fine grains in submicrometer range could be produced by the two-step ECAE.
Careful observation revealed that the grain boundaries are high angle grain boundaries.
In Fig. 2 (b), there are also few dislocations in the interior of grains in spite of large straining by ECAE and effective grain refining.

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.

By contrast, in the work of Xia et al. [11] the nanostructured martensite in Cu-Al alloys obtained by high-pressure torsion (HPT) decomposed to an ultrafine-grained duplex equiaxed grain structure more quickly than in conventional martensite with large lath widths.
The present investigation was conducted to examine the evolution of the structure and the phase composition of the Cu-Al alloy subjected to HPT under different numbers of rotations.
Figure 1(a) shows the as-received sample with an average grain size of ~1 mm.
For the HPT-processed samples, the microhardness becomes higher because HPT leads to a refinement of the grains [12, 14].
It means also that decomposition of the nanostructured martensite includes inhomogeneous nucleation and grain growth.

A possible process characteristics the total cutting contact AK which is calculated from the number of active grains Nakt and the single grain cutting contact AGK (Fig. 3).
The number of active grains depends on the geometrical contact length lg, the number of grains per grinding layer volume unit NV and the cutting area depth z.
Thus the number of active grains increases.
The number of active grains Nakt can be calculated with the approach of Lierse and Tönshoff (Eq. 1) [10, 11]: Nakt=lg∙NV∙c2+1NV∙c1∙ae+vftvc∙lg1c2+1 (1) with c1=43dg (2) c2=32 (3) NV=6∙Cπ∙dg3∙ρg (4) lg=ds2∙cos-1ds2-aeds (5) c1 and c2 are empirically deduced for a round grain shape by Lierse, dg is the grain size ρg is the grain density, C is the grain concentration and ds is the grinding wheel diameter.
The total cutting contact AK, which is the product of the number of active grains and the single grain cutting contact, rises with increasing infeed ae and feed rate vft and decreases with increasing cutting speed vc.

Green color grain (#2) favorites tension twinning.
From the misorientations of #5 grain with #1 grain (～86°<110>) and #2 grain (～60°<100>)[12] shows in Fig.4d, this is another type of variant of tension twins.
Compare with the matrix, these grains have high quality of Kikuchi band, displayed as grain growth approaches twin boundary.
Under uniaxial tensile condition, the number of tension twin variants has relationship with original orientation explained as follow.
But it is worth to note that the observed variants can be formed at different time; also, limited by 2D testing technique, observed number of variants is less than the result from theoretical calculation.

A number of articles have been written about the mechanisms and kinetics of spheroidization [1-2].
Even numbers (2, 4, 6, and 8) can be used to represent to compromises among the preferences below.
An expert in the end determined the preference numbers in the choice for each pairwise comparison.
The numbers of dimple fracture are much more, and its width-depth are bigger in the optimized material than other annealing materials.
Mullins, Grain boundary grooving by volume diffusion, Trans.

Particle numbers were measured using the line interception method, and the particle density ratio for positions 1, 2, 3 is 1:1.7:2.1, where particle density is defined as the number of solid particles in the observation fields in Fig. 3.
Grain diameter is defined as the longest axis of the grain, roundness is defined as the occupied area of the grain divided by the corresponding circle area calculated by the defined grain diameter, and solid fraction is calculated by the total grain area divided by the total area observed.
This suggests that the shape of the grains is controlled by the value of ΔT, with a lower value of ΔT producing more spherical grains.
Even though copious nuclei are formed after pouring, but some nuclei would grow earlier and faster than the others, small grains will disappear, then the survival ratio of grains was small at the surface due to competition growth, see Fig.4 (a), less grains are kept, grains have dendrite shape.
This is the reason why large dendritic grains were present at the slug’s surface, with finer quasi-spherical grains at mid-radius and center. 3.

It is a material based on a fine-grained cement-based matrix, fiber reinforced, fabric of acrylic-resistant glass, basalt or carbon reinforcement.
The concrete had a fine-grained matrix according to a recipe designed at the Klokner Institute.
The material properties of the matrix and of the glass reinforcements were determined by a number of accompanying tests.
Load displacement diagram: Three thin-walled elements - plates (Tab. 1) made from fine-grained concrete - were subjected to a four-point bending loading test (Fig. 1).
There is also a significant shift of bands around 1000 cm-1 range towards lower wavelength numbers.

The grain size is 24~28μm.
The grains are not homogeneous, and the average grain size is about 10 μm.
The dislocation pile-up consists of a large number of dislocations which are intensive in the front and sparse at the back.
Furthermore, a large number of dimples, which present echelonment along the depth direction, appear in the position of fracture.
In fact, the microstructure of the tested steel becomes more uniform and the number of dislocations decreases after solution treatment.

The number of items is seen as a possibility [7, 8] as well as the difference in nature of the sintering defects, thus criteria for rupture.
This may provoke either increased densification and/or uncontrolled grain growth.
Micromechanical Modelling Porous ceramic may undergo a number of micromechanisms of crack extension [22, 23].
Instead does failure arise from the coalescence of a number of individual micro-cracks.
Energy criteria for grain boundary failure are considered in the elastic material.