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The grain size measurement was performed using the standard point count method.
The average grain size in as-wrought condition is approximately 28µm.
The average grain size of this specimen is around 72µm.
This might be due to the small number of five measurements per specimens being performed and that the indents might fall in small grains and large grains or in the middle of the grains or at the twin boundaries or grain boundaries.
With longer annealing time at 1065oC, the recrystallization and grain growth take place resulting in larger grain sizes with decrease in hardness.

SEM shows that the samples contain MgB2 grains with average grain sizes of about 250 nm.
The grain morphology and microstructure were also examined by SEM.
Large numbers of spherical holes with a size of about 10-15 µm can be seen in this image.
The Tc onset for the undoped sample (~ 38.9 K) is almost the same as that reported by a number of groups.
SEM shows that the samples are very porous and contain MgB2 grains with average grain sizes in the sub micron range.

In order to realize this aim, a grain-coarsening simulation was used [2] by means of which an optional coarsened single-phase grain structure could be developed - it can be seen in Fig. 2.
The grain boundaries mean the boundaries of the earlier austenite grains.
By modifying the simulation, it became possible to coarsen smaller grains inside the grains obtained previously (Fig. 2.b) that will later indicate the boundaries of pearlite colonies.
By supposing the Neuman- neighbourhood, the concentration of the i, jth cell in the h th time-step is as follows: ( ) 1 , 1 , 1 1, 1 1, 1 ,1 1 ,1 2 , 4 − − − + − − − + − − +⋅−+++⋅ ∆ ∆⋅ = h ji hji h ji h ji h ji h ji h ji CCCCCC x tD C (6) where h - number of Cell Automation Step (CAS), (number of time step) i - cell row, j - cell column, D - diffusion coefficient ][ 2 sm , t∆ - one time step ][s , x∆ - the size of one cell ][m .
The following parameters are used in the course of the simulations: - CT °= 800 , - s CAS µ9,454= - distance of lamellas ms µ1= , - number of columns 600= , - number of rows 800= , - sm T D /; 314,8141500 exp101,2 2 5       ⋅ − ⋅⋅= − γ [4], - 0=αD (the carbon diffusion through the alpha phase has not been taken into consideration).

With the increase in zinc content, cast microstructure grain boundary 2 # to 4 # alloy increasingly blurred, black mesh compound microstructure mainly, and the number of compounds increases with increased zinc content, can be speculated that the black mesh compound zinc phase.
This is mainly due to the formation of black mesh zinc-rich phase was squeezed broken after the second phase particles and fine particles, pinning grains and inhibit the dual role of dynamic recrystallization grain growth, so in the Mg-6.0Zn-0.6Zr-1.0Y alloy, even at a high temperature of 400℃ extruded through dynamic recrystallization to refine the grains is very effective.
As the Zn content increases, the melting point are decreased, this may be due to the increase of Zn content, resulting in the precipitation amount of the second phase of the Zn-rich phase to further increase the number, thereby reducing Zn in Mg solid matrix solubility, melting point of the alloy decreases[6-8].
Conclusions With the increase in the zinc content of the alloy is gradually squeezing uniform, almost no abnormal growth of the grains, the basic uniform equiaxed fine, and with the increase in the zinc content of the grain becomes smaller.
Effect of grain refinement on tensile ductility in ZK60 magnesium alloy under dynamic loading[J].

The total number of layers was 188.
The goal function is adapted to the following form Φx=i=1Mj=1N(Tijc-Tijm)2 (4) where Tc, Tmare the calculated and measured temperatures, corresponding, M is the number of measurements per time, and N is the number of measuring points.
The mean grain size after last rolling pass was determined in [17] as 40 µm which is used as an initial grain size.
Fig. 3b depicts the distribution of the static recrystallized grain size after 10 s cooling.
The fully recrystallized average grain size was calculated about 13 µm.

Grain size and morphology are also vital for perovskite SC and LED performance.
Tape delays evaporation of DMSO solvent and reduces the number of defects due to long crystallization time.
Liquid phase bonds adjacent grains and remelts grain boundaries [15].
This in turn reduce number of recombination centers and improve SC characteristics.
The number of surface defects affects PLQY, therefore solvent vapor treatment would strongly affect its value.

The pore morphology and microscopic grains of 20 vol% and 30 vol% Al2O3 ceramic foam are shown in Figs 2 and 3.
This is because sintering additive has played the role of restraining grains` abnormal growth, gaining more inerratic, complete and uniform grains.
By adding the sintering additive, there are spinel, anorthite and a small amount of mullite phase generated, pining at the grain boundary, effectively restraining abnormal growth of grains, consequently promoting densification process.
The generating second phase MgAl2O4 which pins at the grain boundary can effectively restrains abnormal growth of grains, consequently promoting densification process and improving mechanical property.
On account of the lattice constants similar to Al2O3, TiO2 usually generates continues solid solution or limit solid solution with Al2O3, inducing lattice distortion for activation and making large numbers of defects or vacancies to enhance diffusion speed.

There are two principal types of electrical steel: grain-oriented and non-oriented silicon steels.
Grain-oriented silicon steel is widely used for power and distribution transformer cores [3].
Moreover the detection of these temperatures for the individual steel is quite important because it is optimal for the grain growth of ferrite grains.
Over this temperature, the α and γ phases coexists and the ferrite grain growth is pined by the γ grains.
APVV - 0147 - 11 and Slovak Grant Agency under the contract number VEGA-2/0083/13.

Additionally, Cr2N, the main precipitation phase, nucleates at austenitic grain boundary and grows towards inner grains with a lamellar morphology.
Table 1 The chemical compositions of tested steels (wt.%) Number Smelting Mode Cr Mn N C Fe No.1 ESR 19.2 17.0 0.44 0.160 Bal.
The microstructure of No.1 and No.2 steel with 0.44% N indicate the stable γ phase and secondary phase in the grains and grain boundaries.
However, Cr23C6 and σ phase disappear in the interior of the grains and a small amount of nitrides exist only at grain boundaries of No.3 as-cast steel
Additionally, Cr2N, the main precipitate, nucleates at austenitic grain boundary and grows towards inner grains with a lamellar morphology.

Citation & Copyright (to be inserted by the publisher ) Research on Ultrasonic Honing Performance of ZrO2 Engineering Ceramics Using Diamond Oil-stone with Coarse Grains F.
The experiments of common and ultrasonic honing ZrO2 engineering ceramics using diamond oil-stone with coarse grains were carried out in this paper.
But those researches are all under the condition of adopting superfine abrasive grains.
The lower temperature of grinding zone in ultrasonic honing can not only keep the sharpness of abrasive grains but also heighten the removal ratio of material.
The engineering ceramics can be machined in ductile mode using diamond oilstone with coarse grains if adopting ultrasonic vibration honing.