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In order to improve the accuracy of quantitative calculation of abrasive flow machining, the influence of geometrical parameters of abrasive grains on machining is analyzed by representing the geometrical shapes of abrasive grains with three parameters, namely height of abrasive grains, cone angle and wear height, establishing the calculation model of blunt conical abrasive grains for abrasive flow machining, deducing the force formulas of abrasive grains and calculating the maximum cutting depth in the event of smooth flow of abrasive grains in the boundary layer.
To solve this problem, researchers have made a large number of studies on the mechanism and quantitative calculation of abrasive flow machining in recent years, for instance, Haan put forward that the existence of decentralized pressure in abrasive flow machining can increase the cutting action of abrasive flow [1], Jain brought forward a calculation model of abrasive flow machining based on neural network method [2, 3], Gorana established the mechanical model of calculating the force of spherical abrasive grains, deduced the calculation formula of axial force and radial force, and made experimental verification and comparison [4], Kar, Tang Yong, Zhao Jia et al.
In the calculation model of the forces of abrasive grains, abrasive grains are surrounded by viscoelastic polymer carriers.
Position of the abrasive grain x = 20mm.
Fig. 4 Correlation between the grain size a Fig. 5 Correlation between the cone angle θ and cutting and cutting depth h of abrasive grains depth h of abrasive grains (Granularity remains unchanged) Fig. 6 Correlation between the wear height ∆a and maximum cutting depth h of abrasive grains Conclusions Three geometrical parameters, namely height of abrasive grains, cone angle and wear height, all have significant influence on the maximum cutting depth of abrasive grains, wherein the grain size parameter a has great influence and can be controlled by selecting different granularities of abrasive grains.

Results Grain Growth.
Recrystallization and Grain Growth.
Subsequent grain growth is affected by Nb in solution and Sarkar et al. [5] showed that the grain growth rate can be described by (5) where M is the grain boundary mobility, g is the grain boundary energy and P is an effective pinning parameter.
It is still required to develop more accurate grain size calibration relationships for these steels, i.e. currently laser-ultrasonic measurements have to be supplemented with a limited number of metallographic grain size measurements to benchmark the laser-ultrasonic data.
Even so, laser-ultrasonic measurements provide entire grain growth kinetic curves as long as the grain structure can reasonably be described with an average grain size.

l Grain samples.
Each grain type contained 360 kernels.
The aim to the analysis was to classify the objects derived by image processing into a defined number of the classes according to their specific features.
Classification of cereal grains using machine vision: I.
Shape analysis of grains of Indian wheat varieties.

Mean grain size.
For very large grains only the center of individual grains was indented.
With decreasing grain size five different segments for nanohardness (labeled as number 1, 2, 3, 4, 5) and two segments for modulus (labeled as number I and II) can be observed. 3.3.
It has been revealed by simulations[17, 18] that the strength of NC Cu decreases with decreasing grain size in the grain size range of 3.28 to 6.56 nm, where the NC Cu deforms via a large number of small “sliding” events of atomic planes at grain boundaries, with only a minor part being caused by dislocation activity in grains.
It is has been reported that the diffusivity of impurity elements (like sulfur) in Ni is several orders higher than the self-diffusivity of Ni at high temperature [28], therefore impurities such as sulfur are expected to segregate to the much smaller number of grain boundaries of larger grains at these annealing temperatures.

A huge number of three-dimensional micro cuttings are performed with different shape of grains.
A number of grinding experiments with a single abrasive grain were performed [1, 2, 3].
On the other hand, a number of finite element models had been presented to describe the metal cutting processes [4, 5].
Single Grain Cutting Model There are mainly three aspects which influence the results of single grain cutting, grain, workpiece and cutting parameters, as show in Fig. 1.
It is regarded cutting with ball-shape grain.

Preparation of Al-Ti-B-C Master Alloy and Its Grain Refinement Effect for Pure Al Z.Q.
The produced Al-Ti-B-C master alloys exhibited high grain refinement effect for pure Al.
The refinement efficiency of this master alloy, however, is reduced when elements such as Cr, Zr, Li, Si are present in aluminum; TiB2 particles in this master alloy are coarse and prone to agglomeration in Al melt, causing a number of product quality problems.
Results and discussion Two typical Al-Ti-B-C master alloys, Al-8Ti-2.4B-0.67C and Al-5Ti-0.82B-0.23C (the number before each element is its content in wt.% in the alloy) were produced in this work, and Fig.1 shows their XRD traces.
Since the formation of α-Al grain based on TiC/TiB2 particles occurs only when the supercooling at the particle-melt interface reaches a certain critical value[1], the additional supercooling due to Ti solute results in the incerasing of the number of effective nucleation sites.

In order to control WC grain size and get a microstructure with fine grain size during the sintering process, WC grain growth in WC-Co cemented carbide was investigated.
The possible reason on the grain growth was showed which includes the normal grain growth (NGG) and the abnormal grain growth (AGG).
Ostwald ripening means large grains growing at the expense of small grains.
But the shape of WC solid grains is faceted, and abnormal grain growth (AGG) is often observed; a few grains grow exclusively while the growth of the other grains is suppressed.
It is observed that the grain size of WC increases rapidly with increasing temperature and there are more pores in number at 1150 o C than that at 1200 oC.

The images of iron contaminated grain boundaries in multicrystalline Si are obtained.
It is shown that the grain boundary XBIC contrast is 2-3 times smaller than the EBIC one.
The dependence of grain boundary XBIC contrast on the X-ray beam width is calculated.
As our estimation shows only about 20% of a total number of generated excess carries is collected due to the limited diffusion length value (25 mm).
EBIC (left) and XBIC images (right) of two grain boundaries in mc Si.

Microstructures formed by the hot-rolling were confused to be observed by an optical microscope and SEM, awing to a number of fine precipitates.
Solid lines show large angle grain boundaries, in which the difference in orientation between the neighboring grains is larger than 15 degree, while fine lines show small angle grain boundaries.
many small angle grain boundaries are observed in larger grains, while they are less observable in smaller grain.
The smaller grains were formed by dynamic recrystallization during hot-rolling remaining strained large grains.
Averaged grain size in (a) was about 10 µm, but the microstructure was composed of extremely fine grains and coarse grains.

Introduction Grain refinement is desirable, especially for high performance applications.
There are few means available for grain refinement such as the addition of grain refiners (Chemical refinement) or through the application of external forces on a melt (Physical refinement).
Grain sizes were measured according to ASTM E112-96 [10].
[[The average grain size achieved when treated below the liquidus was around 102µm as compared to an average grain size of 43µm when the melt was treated above the liquidus, challenging the idea of achieving a fine grain size by implementing below liquidus shearing i.e. in the semi-solid region.
St.John, An analysis of the relationship between grain size, solute Content and the potency and number density of nucleant particles, Metall Mater Trans A, 36 (2005) 1911-20