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In diamond wheel precision grinding process, the grinding force of nano-ceramic coating materials can be divided into single grain grinding force and wheel unit area grinding force, this paper studied the two grinding force, results showed that, with the increase of grinding depth, grinding wheel per unit area grinding force and single grain grinding force increased.
Grinding Wheel Particle Size Effects on Grinding Force The unit area normal grinding force in large size abrasive grinding wheel is bigger than it in small grit size grinding wheel, This is because the grinding forces are generally composed of two components of the chip deformation force and sliding frictional force. the number of effective abrasive grains is large , which involved in grinding in small grain size grinding wheel, in the grinding process, three kinds of sliding friction effection is large among wheel binder, wear debris, and the milled workpiece, so the unit area of grinding force is larger ( the tangential grinding force increases larger ).
The grinding force in per unit area of different particle size under different gringing conditions is discriminate , under the same kind of binder, the smaller the grain size number is, the smaller the grinding force of the unit area is , and this is because the unit area number of effective sharpening is different from different granularity number wheel, the more smaller the size number in per unit area is , the more less grinding sharpening is, per unit area total grinding force is low.
However, the more smaller the grain size number is, the more larger the single abrasive grit grinding force is, this is because the particle diameter is larger, single grain grinding depth increases, the contact area of the grinding wheel and the workpiece increases, which leads to a single mill grain grinding forceincrease .
When the abrasive grain size is reduced, the total grinding force increase in the grinding process, but single abrasive grinding force decreases .

These bands normally initiated at grain boundaries and were restricted to the area of one grain.
In the medium-SFE Cu-10%Zn alloy, the grain morphology became blurry and SBs were readily observed in most of the deformed grains.
After two (Fig. 2(b)) and four (Fig. 2(c)) passes, the microstructures in the three materials were further refined and the density of SBs increased with the pass number.
The incomplete central symmetry can be attributed to the coarse grain size at this stage, such that only a small sampling of the grains were measured in the XRD measurements.
For a given pass number, the texture strength was always higher in the pure Cu than in the Cu-10%Zn and then Cu-30%Zn alloys, indicating a weakening of texture with the decrease of SFE.

On the other hand, the grains are also refined.
Grain refinement is an important topic in the studies of Mg alloys because their grain size has great impact on the mechanical properties.
The grain refinement of α-Mg grains can be attributed to the combined influence of TiC and Al4C3 particles.
The other is the change of morphology, number and distribution of the I-phase.
(2) The combined effect of TiC and Al4C3 particles results in the grain refinement of α-Mg grains

Grinding Simulation Surface plunge grinding using a straight wheel is simulated by the Monte Carlo method, and the traces of cutting edges that pass through a cross section set up in the workpiece are investigated in terms of the number of effective cutting edges, the grain depth of cut and the ground-surface roughness.
The cutting-edge density is calculated using the concentration C and the grain diameter dg assuming that the diamond grains are spherical with diameter dg and that each grain has one cutting edge on its top.
Figure 7 shows SEM images of a diamond grain before and after truncation.
The tip of the diamond grain is flattened without microfracture, although there are small pits of less than 1 m diameter on the grain surface, as shown in Fig. 7(c).
The number of these pits decreases and the area of plastic flow or ductile-mode grinding increases gradually with increasing truncation depth.

A considerable number of dislocations exist in the grains and grain boundaries, which may accommodate a high density of strain energy.
The grain size distribution inserted was measured from a number of bright field and dark field TEM images by number-averaging the diameters of 200 grains.
The grain size ranges from 15 nm to 300 nm, and the average grain size is about 100 nm.
The SMAT sample shows smaller value as compared with coarse-grained one.
Figure 4 is the worn surface morphologies of SMAT Ti and coarse-grained counterpart.

For example, one can investigate the grain size due to deformation in a metal.
The electronic circuitry measures the number of events vs. the delay time between the start and stop signals 2-2.
More detailed measurements of e+ annihilation on fine-grained ZnAl alloys as a function of the mean grain size were also reported by [12,13].
For large grain sizes, the mean lifetime t varies linearly with the inverse grain size l-1, in agreement with most of the available experimental data [13].
The comparison of observed‘d’ values with standard ‘d’ values (PDF number 04-0787) indicates that the 5251Al samples are polycrystalline and have face centered cubic structure.

Microstructures and mechanical properties of as-received and ECAP deformed samples were investigated as related to the number of ECAP pass for better understanding of the effect of multiple-pass pressing.
Although many grains were already significantly refined after only 2 passes, the grain structure was not homogeneous with very fine grains of 5–8 μm as well as coarse grains of greater than 15 μm.
And there were coarse grains surrounded by fine ones.
Since the grain size decreased monotonously with the number of passes, factors other than grain sizes should be considered.
Fig. 2 Dependence of (a) ultimate tensile strength and (b) elongation on the number of ECAP passes Conclusions (1) AZ61 magnesium alloy was successfully ECAP deformed for up to 8 passes at temperatures as low as 473K and the average grain size was considerably reduced from over 26 μm to below 5 μm

We can find small grain size, most grains are tiny and continuous crystal structure.
The number of island is also large.
Fig. 4 Section micrograph under different temperature Picture (a) shows SEM morphology when substrate temperature is room temperature, large number of cores are obtained and grain is tiny; picture (e) shows SEM morphology when substrate temperature is 450℃, the size of grain is large and grain boundary is obvious, which consistent with that of using alloy target [9].
Thus, when the substrate temperature is low, the atom diffusion ability is also low, and the number of island is large.
The final grain is coarse.

This phenomenon strengthens with a further increase in the number of passes and the grain structure almost vanishes after the fourth pass: the grains appear in the form of parallel lines (Figs. 8d and 8e).
At the same time, porosity between the grains also changes, circular pores can be observed between the initial equi-axial grains, while part of them close and cease to exist with the number of passes, and while those remaining become elongated.
For a sintered sample this is 1 or a value close to 1 due to the initial equi-axial grain shape (the number of the horizontal and vertical sections is nearly identical).
In the case of grains becoming more and more elongated with an increase in the number of passes, the value of anisotropy decreases, for the horizontal number of sections decreases and the vertical increases (Figs. 1c and 8e), i.e. the value of the fraction tends to zero.
The grain structure of the deformed samples follows a directional structure identical to the direction of the deformation, and develops gradually with increasing the number of passes. 3.

When the temperature increase to 400 ℃, with the grain boundary further nucleation, the increased small grain further refine the grain scales (figure 1 (c)), and small grain still mainly distributed around the grain boundary.
Dispersion particles can effectively pinning the grain boundaries and restricts grains grew up, which play an important role at the refine grain size.
Tiny grain appears not only in the grain boundary, but also in the grain, grain size scale further decrease.
Deformation temperature influence the second phase of alloy, the second phase size, number, distribution and the fracture mode.
With the deformation temperature increase to 480℃, grain size become small, the dimple number in the fracture increase gradually, and existing a number of the second phase particle in the dimple.