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However, the number of commercially available magnesium alloys is still limited especially for SSM.
Between the dendritics, the intermetallic phases are present at the grain boundaries.
Heated at 575℃ for 10min, the dendritic grains of ZA66 magnesium alloy specimen in as cast state had transformed into globular structure.
With the holding time increasing from 20 to 50min, the liquid is dispersed continuously along grain boundaries, and the amount of liqiuid phase increases.
The ZA66 magnesium alloy exhibits a unique microstructure featuring primary α-Mg grains, β-phase (Mg17Al12) and τ-phase Mg32(Al,Zn)49 intermetallic.

In the theory, a problem is represented by a triplet (X, f, T), where X-the universe with the finest grain-size, f-the attribute of X, and T-the structure of X.
When we view the same problem at a coarser grain size, we have a coarse-grained universe denoted by [X].
According to the granular computing theory, image segmentation actually is a process which transforms the image from fine-grain space to coarse-grain space, and it is a special case of granular computing.
(4) Regard the numbers and values of the centers as the initial points and means that the K-means clustering needed
For j=1, 2, ..., l, calculate the new cluster centers, and update the mean : (3) where Nj is the number of pixels in Qj(i) 3.

The interfaces between the cBN grains and the surrounding matrix are almost straight lines, and no reactions between the cBN grains and the matrix were revealed in SEM observations.
By machining the parts directly after they are hardened, hard turning offers a number of potential benefits over traditional form grinding, such as the lower costs of the equipment, shorter setup time, fewer process steps, and elimination of the cutting fluid.
PCBN can be built of micrometer-sized cBN grains dispersed in a matrix composed of metal carbides, nitrides and oxides.
It can also be seen that the interfaces between the cBN grains and the surrounding matrix are almost straight lines and that (the SEM observations do not show) no major reactions between the cBN grains and the matrix.

The microstructures of Mg alloy were looked cracked in their grains at the thermal oxidation temperature over than 200 °С.
There are a number of method to deposit MgO on the surface of magnesium alloy.
The untreated AZ31 microstructure (Fig. 3a) revealed that the grain were like granular forms.
The form still granular and the surface also still same with the untreated Mg. at the higher temperature, the grain looked cracks on the surface of microstructure.
This crack numbers increased by oxidation thermal temperature.

The model was used to simulate 3-D columnar growth of sixteen grains and 3-D equiaxed growth of a single dendrite of AZ91D alloy.
The kinetic undercooling and melt convection are neglected, and the current model is only valid for growth at low Péclet number (usually Pé<1).
The interface curvature of S-L interface is calculated by the counting-cell technique [8]: ( ) s�ff s � i i s ∆      +      +⋅−= ∑= 1 1 21 1 κ (5) where isf is the solid fraction of cell i, � is the number of neighbor cells, s∆ is the average size of the orthogonal mesh.
Fig.3 (a) and (b) show the morphology of the 3-D columnar dendrites when the solid fraction of the whole calculation domain is 5% and 10%, respectively, where the grains are identified by different colors.
(a) (b) (c) Fig.3 The 3-D simulation results of columnar dendrites of AZ91D Mg alloy with sixteen grains.

The microstructural characterization revealed that adding proper ZrO2 nanoparticles to the matrix can greatly strengthen the grain boundaries, causing more transgranular fractures and consuming more fracture energy.
It showed that adding proper ZrO2 nanoparticles to the ceramic matrix can greatly strengthen the grain boundaries of Al2O3-TiC-ZrO2 micro-nano-composites, and transgranular fracture can consume more fracture energy, thus improving the flexural strength of the nanocomposites.
When the volume fraction of ZrO2 nanoparticles increased gradually, the number of ZrO2 nanoparticles was becoming more and more, which exceeded greatly the number of the micro-particles.
The microstructural characterization revealed that Adding proper ZrO2 nanoparticles to the matrix can greatly strengthen the grain boundaries, and causes more transgranular fractures which consume more fracture energy, thus improving the properties of Al2O3-TiC-ZrO2 micro-nano-composites.

Fig.4 is the S-N curve of experimental steel, which shows the relationship between the maximum stress and the number of cycles.
Under the action of cycle stress, dislocation increased and moved along the slip system from transgranular to grain boundary.
Then the dislocation proliferated in the sub-grain boundary place and formed high-energy dislocation wall.
When the cycle reached a number, the energy of dislocation wall was too high to maintain balance, so the dislocation wall decomposed and dislocation continue moving to the grain boundary which caused fatigue initiation later.
Fatigue crack initiated through dislocation movement and pile-up at the grain boundary.

This is because the number of the abrasive grain grinding on the unit area of the work-piece decreased when the horizontal feed rate increased.
And magnifying the load on each abrasive grain also increases the value of surface roughness [7].
Because the vertical feed is faster, the each abrasive grain sustains the heavier load.
This is because when the tool rotational speed increases, the number of abrasive grain involved in grinding in unit time too increases which reduces the load on single particle, the wear scar becomes thin, and therefore the roughness is low.
Finally, makes the ultrasonic vibration system solid and tests its feasibility by large numbers of experiments.

In this regard, the growing number of windmills and solar power plants attract the special attention of scientists, in particular, questions about how to make them more efficient, cheaper, and the adopted environmental standards regulate the reduction of waste and the possibility of recycling materials.
The Problem Currently, in connection with the sustainable development program, the use of wind turbines is increasing every year. [1] In this vein, the number of wind generators installed in the open sea or coastal area is increasing.
Below, in the text of the work, you can see the tests carried out on the AlM composite, to identify its suitability for use in aggressive marine environments.in connection with the sustainable development program, the use of wind turbines is increasing every year. [1] In this vein, the number of wind generators installed in the open sea or coastal area is increasing.
It can be seen that the original sample tissue distribution is not uniform, there are large grains and small grains, and the two are distributed between the two, the maximum grain size is 22.21 um, the minimum grain size is 0.99 μm, and the average grain size is 5.83 μm.
The time limits for measuring corrosion tests The group Soaking time, h Type number Pre-corrosion weight, g Weight after corrosion, g Weight loss, g 1 0.0277 0.0276 0.0001 1 1 2 0.0288 0.0288 0.0000 3 0.0364 0.0363 0.0001 4 0.0340 0.0338 0.0002 2 5 5 0.0294 0.0293 0.0001 6 0.0313 0.031 0.0003 7 0.0300 0.0295 0.0005 3 12 8 0.0287 0.0284 0.0003 9 0.0330 0.0324 0.0006 10 0.0309 0.0304 0.0005 4 24 11 0.0328 0.0325 0.0003 12 0.0290 0.0284 0.0006 13 0.0330 0.0323 0.0007 5 48 14 0.0319 0.0314 0.0005 15 0.0275 0.0267 0.0008 16 0.0299 0.0291 0.0008 6 96 17 0.0286 0.028 0.0006 18 0.0330 0.0321 0.0009 19 0.0309 0.0299 0.001 7 144 20 0.0308 0.03 0.0008 21 0.0335 0.0324 0.0011 Figure 6.

Here the structure turns into bcc and the number of slip systems rises to twelve.
The higher number of slip systems leads to lower forming forces and a higher formability.
The first intent was to find out, if the temperature influences the grain structure.
The left photo features a small grain size, which is normally desirable.
At a forming temperature of T = 950 °C the grain size is a little less fine than at T = 850 °C, but due to the dynamic recrystallization the grains are homogenously distributed over the whole cross-section.