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The conventional grinding wheel which usually consists of a large number of small abrasive grains held together by a suitable binder.
However, abrasive grain wheels share some common shortcomings, that is, the grains are easily torn form the wheel surface even under normal grinding conditions due to their small bonding areas[2], and the abrasives are randomly distributed without preferred positioning and orientation, which results in the high specific grinding energy and temperature rise，high ratio of normal to tangential grinding force, and large deflection in the grinding system.

As a new kind of red long afterglow phosphorescent materials system, the luminescence properties of titanate perovskites doped with trivalent praseodymium have been increasingly investigated since the mid-1990s due to the potential interest of these red emitting phosphors for display applications [2,3].From then on, a number of studies have been dedicated to the improvement of the emission intensity by varying the method of preparation.
Fig.4 The emission/excitation spectra of Zn0.2Ca0.8TiO3:0.1Pr3+ at 900 oC Morphology analysis The sol-gel technology is a very powerful method for preparing inorganic polycrystalline compounds with controlled grain sizes, morphologies and textures either in the micrometer or in the nanometer scale (Fig.5).The obviously agglomeration happened in figure 5(a).
From the partial enlarged view (b) of Zn0.2Ca0.8TiO3:0.1Pr3+ phosphor, grains with definite shapes and sizes distributed uniformly and agglomerated partially.
The best sintering temperature was 900oC.The grains of Zn0.2Ca0.8TiO3:0.1Pr3+ phosphor with definite shapes and sizes distributed uniformly and was quite small reaching nanometer scale.

Fig. 3, shows TEM micrographs depicting the deformed samples consisting of a morphology of elongated nano grained matrix with high dislocation density and grain size of 50nm.
On subsequent annealing at 400oC, no notable change in microstructure was observed except sharpening of grain boundaries.
It was difficult to observe the decomposed microstructure because of the high degree of deformation and the resulting large number of dislocations within the matrix.

The influence of milling time for grain size of Cu-Zn alloy powder Ball milling time (min) 20 40 60 80 100 120 150 D10/µm 9.35 7.64 6.58 4.57 3.96 3.93 3.96 D50/µm 19.86 17.73 15.14 11.57 10.04 9.34 8.85 D75/µm 28.93 25.28 21.39 17.70 15.17 13.84 12.86 D90/µm 41.26 34.31 28.76 24.15 20.69 18.88 17.48 Dav/µm 23.13 19.67 16.69 13.32 11.46 10.59 9.97 Fig. 1. 
The particle size D50 is defined as the grain diameter at which 50% of the powder sample is under this size, D10 and D90 are associated with 10% and 90% as the same means.
It had decided the quantity of powder, which had been cought and the number of effective collision times when the collision happened, in order to study the effects of the ball-to-powder ratio on the phase form, XRD analysis had been made after 10:1,20:1 and 40:1 three ball-to-powder ratio milling, the result has been as follows: Relations between energy consumption and morphology of powder and technological conditions have been determined by testing, as can be seen from the graph.
The final phase of two different speed was analyzed, and the result has been as follows: Fig.5 It shows the XRD patterns of Cu-Zn powder milled with different rotate speed, although different rotate speed has influence on particlesize distribution of powder , but the final phase is same, after milling main generated the Cu5Zn8 and the simple substance of Cu, but in high speed, diffraction peak width means finer powders can be obtained with high speed easily consistent with the results of grain size analysis.

Secondly, when a large number of types of dislocation are present (each with different b and/or l), even a full knowledge of a cannot uniquely define the N densities.
It should be recalled that this picture is incomplete because we are only picking up dislocations which thread through the map; but since different grains give the same dominance of basal plane Burgers vectors, regardless of grain orientation, the result is robust.
Note that apart from twins, the uniform colours in each grain indicate a uniform orientation and hence very little plastic strain.

The less the grain size, the wider the diffraction peaks width.
The diffraction peaks of amorphous structure are thoroughly diffuse scattering peak, so it can be concluded that there is no obvious amorphous structure in melt-spin Fe-V-Nb, but the grain size is very small [11].
During the process of melt-spin Fe-V-Nb, the microstructure of Fe-V-Nb intermediate alloy was refined, the pre-nucleus vanadium and niobium in master alloy was increased, and a large number of modifying nucleus the composite carbide was produced in liquid 60Si2Mn in subsequent melting process[12].
Conclusions 1) The Fe-V-Nb intermediate alloy is rapidly solidified with melt-spin method.XRD and TEM analysis show that, under the cooling speed of 40-45rad/s, the microstructure of the ribbon consists of amorphous and nano- grains, the intermediate alloy produces more modifying nucleus composite carbide in liquid 60Si2Mn matrix in the subsequent melting process.

So the variation in the number of particle-like phase is mainly attributed to the change of TiC content.
When the content of TiC is equal to its theoretical content (Fig. 2(a)), Al2O3 and TiC grains disperse uniformly in the matrix.
However, as the content of TiC reduce to 80 % of its theoretical content (Fig. 2(c)), TiC grains increase again and agglomerate seriously around the matrix grain due to the decomposition of Ti3AlC2.

Modification improves the material's mechanical properties through grain refinement.
After modifications the fracture surface consists of cleavage planes and grain boundaries.
Percentage elongation Al-7%SiMg alloy with Na2B4O7+Mg Conclusions The results of the study indicate that grain refinement, tensile strength and percentage elongation increased not only with an increment in modifier content, but also with an increase in the exothermic effects of the modifier's chemical reaction.
The number of reducing agent moles differed between the two reactions to the advantage of magnesium.

The hot junction is formed by plastic deformation induced by grain action and therefore localized directly on the ground surface [6].
Whereas the peak temperature is caused by the individual abrasive grains cutting over the foil–workpiece junction.
As the grinding speed increases, the number of grains per unit time increases, which leads to more finely divided debris and more ploughing and swiping actions.

Udomsamuthirun et al. [2] synthesized the new YBaCuO superconductors by using the standard solid-state reaction method as compositions of Y5-6-11, Y7-9-16, Y358, Y5-8-13, Y7-11-18, Y156, Y3-8-11, and Y13-20-23, where the numbers indicate Y, Ba, and Cu atoms respectively.
The effect of Titanium addition was observed and found that the Ti-doping did not improve the weak-link behavior of the superconducting grains and the critical temperature.
With increase Ti-doping concentration, the grain size decreases up to 0.04%.
For 0.05% Ti-doping, the grain size decrease significantly.