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In this paper, a number of approaches are discussed to control IMC formation in welds between aluminium alloys and magnesium alloy.
(4) where w is the average width of grain boundary, d is the diameter of grains in the direction parallel to the welding interface, and q is a numerical factor depending on the grain shape, q=1 for parallel grain boundaries, and q=3 for cubic grains.
From Fig. 2 (a), all grains of the Mg17Al12 phase (Gamma phase) have a similar grain size, but grain size of the Al3Mg2 phase (Beta phase) is not homogeneous.
For the layer thicknesses and very small grain sizes in the IMC encountered during welding, grain boundary diffusion is thus predicted to dominate.
(a) (b) (c) (d) Figure 3: (a) effect of grain size on grain boundary diffusion, lattice diffusion, and effective diffusion coefficient of the Mg17Al12 phase, (b) effect of grain size on grain boundary diffusion, lattice diffusion, and effective diffusion coefficient of the Al3Mg2 phase, (c) effect of temperature on the diffusion coefficient of the two phases when their grain size is 1 µm, and (d) effect of temperature on the diffusion coefficient of the two phases when their grain size is 10 µm.

The surface grain is nano-size, and the grain size is about 10nm to 20nm.
Experimental results and analysis Fine single-phase austenite equiaxed grains accompanied with a large number of annealing twins can be observed after solution treatment (Fig. 2(a)).
A large number of new extremely fine grains are generated by the slip(Fig. 3(b)).
In Fig. 3(c), the grinding time of friction head is increased to 6 hours, no clear grain boundaries are seen we can see that between the grains has no clear distinction between the grain boundary, grain refinement to a certain extent and formed a large number of clusters flocculent microstructure.
It demonstrate this part of the grain is nano-scale grain.

There have been a number of studies on the corrosion behavior of Si3N4 ceramics at high temperatures such as in molten salts and gaseous environments [2-4].
The as-received specimen shows a dense microstructure and consists of a mixture of small equiaxed and large elongated Si3N4 grains.
It can be seen from the microstructures of the specimens corroded for 0.5 and 1 day that the grain-boundary phase is selectively corroded away, clearly revealing the rod-like Si3N4 grains and resulting in a porous structure.
The diameter and length of Si3N4 grains are getting smaller as the corrosion reaction proceeds.
The as-received specimen shows only the β-Si3N4 phase, suggesting the amorphous nature of the grain-boundary phase.

In order to locate and segment the image of grain bags in the granary reserves, and making full use of the spatial location information of grain bags, a threshold method is proposed base on two-dimensional Fisher criterion.
It is of great practical significance for upgrading the supervision level of grain management.
(3) where, is the integer function, let K that is usually an odd number denote the neighborhood width of pixel (x, y).
In the actual scene of grain bags reserves, the grain bags had the characteristics of relatively consistent, while the gray value of each bag region are concentrated and well-distributed.
In terms of the segmentation results, the traditional 1D Fisher method can segment each grain bag region, but that approach had some segmentation error, caused loss of some grain bag regions.

These grain refinements directly affected an increase in mechanical properties.
As a result, the average grain size was refined to 9.8 mm.
Also, equiaxed grains were wholly distributed in the microstructure, including annealing twins in the grains.
In the case of cross-roll rolled materials, more refined grains (average size 6.5 mm) were obtained; these included annealing twins in the grains, as shown in Fig. 1(c).
The Vickers microhardness numbers of the rolled materials were very similar: 127 Hv for the CR material and 124 Hv for the CRR material, as shown in Fig. 3(a).

Moreover, it is found that the recrystallization temperature of the Al-0.6%Cu alloy samples decreases with increasing the number of ECAP passes.
%Cu alloys subjected to different number of ECAP passes were annealed at different temperature.
The numbers of ECAP passes are 1, 2, 4, respectively.
(1) The grains of Al-0.6%Cu alloy are refined to sub-micron level after multi-pass ECAP
(2) The recrystallization temperature of the Al-0.6%Cu alloy decreases with increasing the number of ECAP passes

Introduction Many damage mechanisms of polycrystalline metallic alloys involve the accumulation of plastic strain and rotation at the sub-grain level, particularly in the vicinity of grain boundaries.
These bands increase in number and intensity with increasing stress level.
A limited number of 6 grains named G1 to G6 are analyzed in the present article.
This slip/strain bands distribution appears to be inhomogeneous within grains and may be directly correlated with the vicinity of double or triple grain boundaries.
Localized strain bands are observed to be often continuous across grain boundaries.

In the present work, results are presented which illustrate both the role of grain orientation and grain boundaries in the corrosion process.
Not only the role of the grain orientation will be investigated, but also the role of the grain boundaries will be taken into account.
From the IPF map (Fig. 1b), it was observed that grain 1 and 3 have an orientation close to <001> // ND while grain 2 is oriented close to <111> // ND and grain 4 has a near <112> // ND orientation.
Three line scans between grain one and two determine the average height difference between these grains (c).
When comparing the FE-SEM view in Figure 5a with the image quality map in Figure 5b, which depicts the different types of boundaries, a number of observations can be made.

And the most important issue in the management of grain reserves is monitoring the temperature and humidity changes in the grain depot.
Wireless sensor network (WSN) is a distributed network [1] consisting of a large number of low-power sensor nodes in a self-organizing way.
Table 1. 64-bit ROM code of DS18B20 CRC Product serial number Product code 8 bits 48 bits 8 bits According to these characteristics of the DS18B20 and the demand of grain storage temperature acquisition, a special temperature cable is designed, as shown in Fig. 2: Fig. 2.
The CTP protocol adopts the idea of collection tree, setting the number of root node in the network.
The total length of the message is 64bytes, and its content is simply the same number, beginning at one.

The relaxation times determined on the basis of impedance data were found to decrease with increasing atomic number of lanthanide.
The relaxation times at 20°C decrease with increasing atomic number of a lanthanide - from 2x10-4 and 2x10-2 s for Nd2/3Cu3Ti4O12 to 3x10-7 and 2x10-4 s for Dy2/3Cu3Ti4O12, for grains and grain boundaries, respectively.
The activation energies of resistances of grains and grain boundaries are close to those of dielectric relaxation.
At a given temperature, it increases with increasing atomic number of a lanthanide.
A higher resistivity of grain boundaries results presumably from reoxidation of copper ions during cooling, which occurs preferentially at grain boundaries, whereas the grain interior contains still Cu+ ions, responsible for a higher electric conductivity of grains.