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We chose GC and WA grains.
The GC grains are commonly used for processing brittle materials, because the particles have sharp edges and possess comparatively higher hardness than WA grains.
The WA grains are comparatively tough.
Fig. 2 shows the effect of the average particle diameter of the abrasive grains on the machined surface roughness by changing the number of blasting times.
Since the mixture ratio of compressed air and the abrasive grains lowers, the interference among abrasive grains decreases.

In the past two decades, a number of researchers have reported on selective corrosion of WC in cemented carbide.
After corroded for 6 hours, WC grains on the surface had been removed completely, leaving a Co layer with WC grains-shaped cavity such as triangular and square shaped cavity on the surface.
With the increase of WC grain size, WC corrosion content decreases.
When corrosion time were 2 hours, the coarse WC grains were found on the surface while the fine grains have been removed completely.
It supports the effects of WC grain size on corrosion rate.

Refining grains are important to obtain sound cast billets suitable for further processing.
With increasing of applying LFEF treated time, the fine grain occupied the whole section of ingot, and the ratio of fine grain zone to the whole section was proportional to the treated time.
The maximum change rate (the largest nucleation rate) was observed from 30s to 70s, which means that solidification front is fragile, and a large number of nuclei can be torn off from the solidification front by the effect of LFEF treatment in this period.
With increasing of LFEF treated time, the number of new nuclei has increased, and the ratio of fine grain zone to the whole section has increased gradually with the increase of treated time.
Qian, A Brief History of the Grain Refinement of Cast Light Alloys, Mater.

Study on the evaluation of minor rural road network planning alternative in the state commercial grain base Hongjiang Gao1, a, Zhenni Pan1,b Siling Yang1,c 1School of management Tianjin University Tianjin, China aghj-751018@163.com, bzhenni-pan@163.com, cysl.20021077@163.com Keywords: the minor rural road planning; road network evaluation index; fuzzy entropy weight; double base method ; the state commercial grain base roads Abstract.
Introduction The state commercial grain bases is a basic form of the agricultural areas division system, and the agricultural professional area, the function of which is grain production primarily and providing commodity grain and other related agricultural products for social and economic development [1].
(2) Where is the road network connection degree, the total number of road network node; the adjacent edge number of the No.i node.
Patch density, patch number, patch area and so on, all affect the rural landscape fragmentation
(7) Where, is the total number of the cultivated land patches, the average area of the cultivated land patch.

Introduction Since both strength and toughness can be improved by grain refining, the grain refinement is important to create high strength steels.
As indicated by an arrow in Fig. 3a, continuous-recrystallized (recovery and/or grain growth) grains were observed locally.
The tensile strength, TS, increased with number of turns, and that of specimens for N = 5 and 10 showed the extremely high strength of around 1900 MPa, as shown in Fig. 5a.
It is also noteworthy in the tensile property of HPT processed disks that the total elongation, EL, increased with strain from eq = 45 to eq = 91 (number of turns from N = 5 to 10).
Such yielding behavior seems to be ascribable to the difficulty of dislocation nucleation in submicron-grained structure with stable grain boundaries [14].

Although a few number of publications on the microstructural evolution occurring during warm deformation of plain carbon steels have been reported [14, 15].
At this stage, ultrafine grains, even though few in number, are formed at the original grain boundaries and the grains aspect ratio increases along the torsion direction.
Very fine equiaxed ferrite grains surrounded by HABs were generated along the initial ferrite grain boundaries, even though they were small in number.
Additionally, there are a number of incomplete high angle boundaries, i.e. isolated high angle grain boundary segments present in the larger ferrite grains.
This indicates that the grains were formed by a process of fragmentation / subdivision of initial grains.

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

The fluid effect is attributed to the number of active abrasives, but the effects of slurry particles under hydrodynamic contact were not investigated.
Recently, Jeng and Tsai presented and discussed the mathematical formulae for grain/grain collision elasticity, grain size and roughness [23-24].
That is, increasing kw implies the grain-grain collision is becoming more inelastic and makes the energy loss larger.
Our prior works have discussed the effect of grain-grain collision elasticity on the flow factors.
grain/grain collision elasticity, particle size and pad asperity.

It is well known that ultrafine-grained materials often possess superior mechanical properties to those of their conventional coarse-grained polycrystalline counterparts[1-3].
Also several methods for grain-refinement have been developed, few of them can be used in the grain-refinement of pipeline steels.
In this paper, ECP method was applied to X70 steels to refine its grains and improve its mechanical behavior; the mechanism of grain-refinement was also discussed.
In combination with a very short treating time, the newly recrystallized grains have not enough time to grow, and then smaller grains can be obtained finally.
As a result, large numbers of small γ-phase nuclei can be generated in the original α-phase during the heating process in ECP treatment.

In general, the strongest reflections apparent in patterns could be matched with a JCPDS file number 74-1504.
The average grain sizes were checked by linear interception method.
The ZT ceramics sintered at 1450 and 1500 oC showed the average grain size of 8.55 and 12.55 µm, respectively.
At sintering temperature 1550 and 1600 o C, morphology of grains changed to plate like crystals of second phases.
The average grain sizes were checked by linear interception method.