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Nevertheless, the grain distribution uniformity, the grain protrusion consistency and the grain rake angle are main indices of dressing surface quality.
The volume of the discharge crater and the number of protruding abrasive grains increase as the pulse duration increases.
(2) The volume of the discharge crater and the number of protruding abrasive grains increase as the pulse duration, pulse voltage and pulse current increase.
The protrusion height of abrasive grains is also increasing
EDM Dressing of Fine Grain Super abrasive Grinding Wheel.

However, for many practical applications the ability to sinter the powders into dense bodies whilst retaining grain sizes in the nanometer range is a critical step, especially given the challenges of particle agglomeration, high reactivity and inherent contamination that all lead readily to grain coarsening and hence loss of the nanostructure [2].
Previous work has examined both conventional and microwave fast firing [6-8], in which the aim is to suppress grain growth by the use of very high heating and cooling rates and short hold times, and the use of a twostep sintering method [5] where the suppression of grain growth is achieved by exploiting the difference in kinetics between the grain boundary diffusion and grain boundary migration.
Whilst figure 2d indicates that a high density has been achieved and a sub-micron microstructure retained, figure 2c shows the presence of a large number of smooth, approximately spherical inclusions measuring ~1 - 4 µm in diameter and generally containing well-defined cracks.
A much smaller number of similar sized agglomerates were observed in the green bodies, see top right hand a) Densification vs Micronising time 92 93 94 95 96 97 0 2 4 6 8 10 Micronising time /mins
The combination of microwave heating and nano powder formulation was found to provide samples with near zero porosity and an average grain size of 140 nm.

Sample number: 1#－monoatomic zirconia and calcium oxide, 2#－desilication zirconia and calcium oxide, 3#－fused zirconia and calcium oxide.
CaZrO3 synthesis ratio of the 1 speciment is little, and CaZrO3 crystal grain is small.
CaZrO3 crystal grain of the 2 speciment is almost equal.
Though CaZrO3 synthesis ratio of the 3 speciment is most, crystal grain is not integrity.
For the liquid content of 2 speciment is relatively much, CaZrO3 crystal grain grows biggest.

Then the sample surfaces were divided into 25 units numbered 1#~25# in size of 10mm×8mm.
It is seen that the initial abrasive grains have cutting edges upward with sharp pyramid structure (Fig.2a).
Then, the number of wear areas increases, and the areas become larger (Fig. 2c).
Wear area ratio r k2=0.035 k1=0.0048 Units number Units number Figure 3.
The normal grinding force is 3N at the beginning because the cutting edges of abrasive grains are sharp.

Microstructure of the NFA observed by TEM exhibited a very fine structure of nanostructured grains in which large number of nanoscale oxide particles were distributed after HP process.
In this case, the obtained grain size is volume averaged in the direction perpendicular to the plane of diffraction.
Fig. 3 shows the change in the grain size of the powders of Fe-9Cr-0.2Ti-0.3Y2O3 after being mechanically milled for various times.
The change of the grain size can be explained that the abruptly decrease of the grain size is caused by intense collision during the initial stage of milling and the slow variation has occurred along with the formation of the dynamic equilibrium between cold-welding and repeated fracture after longer milling time.
Measured grain size of Fe-9Cr-0.2Ti-0.3Y2O3 powder mixture milled for different periods.

Two types of powder mixtures, namely, nickel mixed with coarse-grained nickel aluminide and nickel mixed with fine-grained nickel aluminide were used to obtain the composites.
Introduction Intermetallic compound Ni3Al and Ni3Al-based alloys are the most promising high-temperature materials for a number of chemical industries, aviation and space engineering.
Long time sintering promotes the growth of Ni3Al grains which is accompanied by mechanical properties degradation.
Powder mixture No 1 was obtained by mixing coarse-grained PN85YU15 and nickel powder in a planetary ball mill Fritch Pulverisette 6.
With decreasing grain sizes and changing the shape of the nickel aluminide powder, ductile fracture is mainly observed (Fig. 5 c, d).

Specific silicon nitride ceramics, the influence of the grain size and orientation on the bridging mechanisms was found.
From a number of damage concepts the cohesive models seem to be especially attractive for the practical applications.
Namely, the effects of the targeted grain structure on the fracture toughness of silicon nitride were demonstrated in [1, 2].
Similarly, the influence of boundary phase manipulation and the effect of grain bridging on the strength and toughness were illustrated in [3].
The detail of very short crack (having length of several grains) is shown in Fig. 2.

Grain size of the ceramics increased with increasing the sintering temperature.
A pure perovskites structure with cubic symmetry were retained in the ceramics sintered at 1400-1450oC which matches with the ICSD file number 01-075-0003.
The ceramics presented regular shaped grains and less pore for the 1450 oC ceramic sample.
The average grain sizes of the ceramics sintered at different temperatures was calculated by the linear intercept method (Fig. 1(b)).
After adding BZT an heterogeneous conduction may have occurred [13] due to BZT and SFN having a large difference of conduction which alter bulk grain and grain boundary characteristics.

After studying the slab of the CSP, the composition segregation and the finished products, we drew the conclusion that the low magnification of CSP thin slab is denser, columnar grain more developed; Loose and segregation exist while the segregation is smaller than traditional one.
After the acid etching of the CSP slabs, we can see with our eyes that for the CSP slabs with a thickness of 50mm, its low magnification looks the same with the traditional slab in structure, just as the columnar grains of the CSP slab develop better; some run across the central part; there are few equiax crystal; there is bridging for the columnar grains, and there are center porosity and segregation at the central line 9（shown in Fig.5）.
Generally speaking, the solidification segregation of cast billet happens because of the columnar grains’ growth, the solute elements of the unsolidificated molten steel in the interdendrite get enriched.
The solidification contraction of the solid-liquid zone of the solidification end makes the enriched solute in raffinate in the columnar grain’s dendrite flow to the center , thus the central segregation is formed.
Conclusion (1) CSP thin slab has denser low magnification, more developed columnar grains, better distributed chemical composition, less center equiaxed dendrite, and in the center exist center porosity and segregation while its segregation is smaller than traditional slab

The coarse-grained method could also be used for the stretchability and fracture behavior process of the polyacrylamide (PAAm) hydrogel system.
The number of ABA triblock copolymer is 200, the volume concentration of ABA copolymer is10%, 20%, 30%, 40%, and 50% respectively.
The number of ABA triblock copolymer is 100, the type is 110-80-110, the water site is 160000, the volume concentration of ABA copolymer is 20%, the temperature is 1.0 kBT / e.
Hall, Molecular dynamics simulations of ion-containing polymers using generic coarse-grained models.
Kubo, Coarse-grained molecular dynamics simulation of the void growth process in the block structure of semicrystalline polymers.