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The gas and smoke absorbed during solidification of short circuited melted mark occurred in such environment will certainly have an effect on grain shape, grain size, holes distribution and impurity element distribution of organization of melted mark.
Introduction With the social development, home appliances are becoming electrified gradually, so the fire caused by electrical equipment is also increasing year by year, the number of which has been on the top of all kinds of fire.
During the 15 years from 1993 to 2007, there were 1,527,600 fire accidents totally in China, wherein, electrical fire accidents were 373,700, accounting for 24.5% of the total number of fire accidents [1,3].
The smoke particle on the surface of the wire during the process of short circuit melt and solidification influenced the nucleation, crystallization, holes formation, grain growth and so on of melting part.
Fig. 4 5g Fig.5 Conclusions The amount of smoke content and the viscosity of smoke in fire environment play a decisive role in the size and distribution of holes, grain shape, melt transition area and etc. of the internal organization of short circuited melted mark.

Atom probe tomography also allows the direct, local investigation of the grain boundary diffusion in any single grain boundaries.
Currently there are a number of reconstruction algorithms available, most of them are based on the model developed by Bas and coworkers [13].
The microstructure of these samples is very fine nanocrystalline with a grain size in the range of a few tens of nanometers.
Such small grain size means, that substructures of the GBs, such as TJs have a reasonably high volume fraction [23].
By contrast, the concentration dependence of the grain boundary diffusion in general high angle grain boundaries is very weak.

SEM micrograph showed the Jc is induced significantly by continuity of grain formation via grain size.
The doping of alkaline-earth metal does not just increase the number of holes in the CuO2 planes, but reduces the current blocking effect of grain boundaries [2,3].
Larger grain size will enhance the grains continuity, lessen the porosity thus enhance the Jc value.
Bigger grain size, minimum porosity and less of grain boundries is also founded with Y123 system.
The existence of impurities (Ca) and the continuous formation of the grain decrease the number of grain boundaries.

The extrusion die is designed to create additional material deformation to a defined depth, resulting in a gradient from ultra-fine grained to coarse grained microstructure.
In the near-surface area an ECAP channel is assumed with several consecutive ECAP-steps which are numbered 1 to 8.
A grain size larger than 50 µm can be observed.
Sub-structuring and reorientation of the grain can be detected.
Furthermore fragments with grain sizes larger than 10 µm can be observed.

Meanwhile, the crystalline grain had a uniformity distribution, and the grain size was about 9.5~10 grade.
When the tempering temperature rose continuously to 640℃, a large number of supersaturated precipitation carbides happened along the grain boundaries, and began to gather and grow forming black network microstructure, as shown in Figure 4(c).
The most numerous of these precipitates were needle-shaped type, while a smaller number of precipitates were club-shaped type.
On the other hand, yield strength of HSLA steels has reached 780MPa [2], which were contributed to the large number of carbide precipitation distributed finely and uniformity.
Consequently, the reduction in the number of M3C carbides leads to an improvement in the fracture toughness [6].

However as seen in Fig. 4, grain boundaries can still be detected using the NUV-PL signal.
Grain boundaries are detected in high doped 150mm substrates.
In wafers that have a high density of these PL signatures a much larger number of ‘V’ type defects and stacking faults were observed in the epitaxial layers.
The defects marked in red are grain boundaries, which also exhibit PL activity.
Grain boundaries in the substrates were detected to isolate defective boules.

The number of cycles to cause complete failure was taken as fatigue life ( fN ).
The alloy after solution heat treatment has an average equiaxed grain size of 110 mµ .
Small discrete carbide particles probably being of the MC types are found to be present in both the interior of the grains and at the grain and twin boundaries.
A TEM observation of the carbide particles in both the interior of grains and at the grain boundaries are typically shown in Fig.3.
TEM observations exhibited that at low strains ( %2.0grains, while at high strains ( %2.0>apε ) large number of slip bands with more than one slip system were seen within the grains.

Elongation rate also fell over the first peak may be due to: non-uniform deformation within the grain and the grain boundary strength increases due to reduced.
This is why grain boundaries off consecutive sub-band structure of the phenomenon.
In addition a large number at the bottom of thick GP conditions for the¢ hzone formation at high-energy distortion field for formation of increased energy.
（a）24h, intragranular （b）24h, Grain Boundary （c）52h, intragranular （d）52h, Grain Boundary （e）76h, intragranular （f）76h, Grain Boundary （g）90h, intragranular （h）90h, Grain Boundary Fig.3 TEM images of 7050 aluminum alloy under various age states 4.
Lead to a large number of grain boundary phase of ¢ h thicken and gradually began to gather over a non-coherent system of h lower energy relative to the direction towards the development of grain boundary off consecutive sub-band structure of the phenomenon

Introduction Ultrafine-grained (UFG) materials processed by severe plastic deformation (SPD) methods exhibit a number of improved properties such as high strength at room temperature, ability to deform superplastically at lower temperatures and/or higher strain rates than fine grained materials, high fatigue resistance etc. [1, 2].
Most probably, during deformation dynamic recrystallization occurs in the grains of the primary a-phase.
[12] ASTM E112-10, Standard Test Methods for Determining Average Grain Size, ASTM International, West Conshohocken, PA, 2010
Froes, Characterization of submicron-grained Ti-6Al-4V sheets with enhanced superplastic properties, Mater.
Valiev, Service properties of ultrafine-grained Ti-6Al-4V alloy at elevated temperature, J.

The higher vibration frequency is, the more the globular grains are and the finer the globular grains is.
The microstructure takes on fine globular grains for lower pouring temperature, whereas many clubbed grains appear when the pouring temperature is higher.
The results show that lower temperature is avail to the formation of fine globular grains.
The increase of the chilling rate can help to obtain more fine globular grains.
Acknowledgements This work is sponsored by the National Natural Science Foundation of China under the grant number of 50471065.