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The results of grain size analyses are shown in Table 1.
When compared to pure magensium, grain refinement (i.e. reduction in grain size) was observed in the Mg-Al alloys processed in both Ar and CO2 atmosphere.
In both cases, the grain size reduced with the increase in the aluminium content (wt.%).
This increase was due to the grain refinement effect [8] and in addition due to the presence of Mg17Al12 intermetallic phase along the grain boundaries, which led to grain boundary strengthening [5].
As magnesium had less number of independent slip systems due to its hexagonal close-packed (h.c.p) structure [8], the deformation of the magnesium alloys was restricted, causing predominant brittle failure with cleavage and quasi-cleavage as the most common fracture modes [10].

With the increase of sintering temperature, on account of the excessively growing of the grain and the increasing of closed pores number, ceramic density decreased.
When x = 0, grain doesn’t get full growth grow and there is lots of cavities between grains, which destiny is about 3.64 g/cm3 (Fig. 3(a)).
That is because of the synthesis temperature of MgTiO3 is about 1450°C and the movement of grain boundary has no enough energy, grain are not fully grown and causing poor ceramic density.
When x = 0.1, 0.2, 0.3, as seen in Fig. 3(b), 3(c), 3(d), grain size is more evenly, between the grain is more tightly and sintered density is good.
When x=0.1, 0.2 and 0.3, the grain of the ceramics were tightly, clearness grain boundary and with high Qf.

The aim of the work is to study highly-dispersed additives on the basis of natural wollastonite and its effect on the properties of fine-grained concrete.
New-formed surfaces have a significantly higher adhesive activity due to the large number of unsaturated valence bonds, thereby increasing the technical specifications of the materials.
Some further increase in the content of the developed additive in fine-grained concrete results in concrete decompaction and strength reduction.
The strength of the modified fine-grained concrete after heat treatment.
The structure of the contact zone of the cement stone and wollastonite particles of the fine-grained concrete samples: (a) plain; (b) modified.

A SEM picture of three neighboring grains is shown in Fig. 3a.
While the grain in the upper part exhibits numerous voids and cracks, two grains in the lower part have a smooth surface with only a few voids.
All investigated AlN grains show Al excess, with the Al content ranging from 54 to about 60 % at in different grains as measured in 70 x 60 µm² Journal Title and Volume Number (to be inserted by the publisher) 3 areas.
FT-IR reflection micro-spectra taken at two different single-crystalline regions and at a grain boundary are shown in Fig. 4.
Differences in surface roughness and void occurrence probably arise from different grain orientation, polarity, and/or impurity incorporation.

The effects of microstructure on the fatigue crack growth behavior have been carried on by a number of researchers.
Otherwise, the size of b grain grows to 60 mm with the clear a boundary, and the width of lamellar a2 is tending to become coarse inside the b grain.
During the increase of the size of b grain (in Fig. 2), the decrease of the ductility and elongation is observed in Table 2.
The effect of the size of b grain on ductility corresponds to a change of fracture mode[11], whereas a ductile intercrystalline dimple type of fracture occurs along the continuous a layers at b grain bandary resulting to the decrease of slip length.
The most influential parameter on the fatigue crack propagation is the a colony and the boundary a of the b grain.

The experimental results show that, the grain size in the range of experiment did not seem to influence desulphurization.
The process not only increased specific surface area of carbon grain in petroleum coke, but also removed 98% of sulfur.
The chosen sample was mixed with NaOH solid grain, then put into a Muffle stove, calcined in set temperature for certain time.
The number is 51074205.

The grain size measured to be about 30nm, and the average particle size after the reunion is 100nm.
According to the XRD spectrum, the grain size and the average particle size after the reunion are calculated to 30 nm and 100 nm, respectively.
Compared to micron crystalline powder, the grain size of the semiconductor Pb3O4 nano-crystalline powder is closely related to its the optical absorption coefficient.
We can find out that the optical and electrical are depend greatly on the grain sizes, shapes, and doping of the semiconductor nano-crystals.
Acknowledgments This work was supported by NSFC(Under Grant Numbers: 60877068).

In addition, more nucleation site are available due to a smaller austenite grain and the increased number of dislocations.
It turns out that with a higher degree of deformation, an increased number of fine precipitates occurs in the microstructure, as shown in Fig. 3.
Due to an increased degree of deformation a significantly higher number of finely distributed precipitates are formed.
Higher deformation degrees reduce the austenite grain size what results in smaller bainitic packages.
Lee, Effect of austenite grain size on the transformation kinetics of upper and lower bainite in a low-alloy steel, Scr.

Grain refinement and precipitation strengthening are the main technical routes to develop high strength steel.
Microalloying has become the mainstream technology of production high strength steel with refined grain and precipitation strengthening effect.
The grains are fine and the size distribution is uniform.
The ASTM grain size number is 11.5.
They found hot-rolled steel sheet existed a large number of nano-scaled precipitated particles less than 20 nm with spinel structure too.

Optical microscopy: the definition of the prior austenite grain size.
Fig. 7 shows the prior austenite grain size of two different bandsaw blade steels. 3.
The number of cycles to failure (N) had been measured and compared in the case of different stress intensity factors.
Map of tempered martensite grains (left) and residual austenite (right).
Acknowledgement The National Scientific Research Foundation supported this research: project number is T43571.