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Results showed that the main microstructure was single-phase austenite grain.
Also lots of twin grains were found in sample c, as was shown in Fig. 4.
Also there existed lots of twin grains in sample b.
Twin grains were one of the main plastic deformation forms of austenite [3].
However, when the stress value was larger than a certain number, the oxide film would be destroyed.

With increasing the calcining temperature of precursor, the grain grew and the size of ceramic powders became bigger.
When the sintering temperature was 1300°C, there were some little holes in the surface, grain fully grew, crystal boundary was clear and size of grain was small.
When the sintering temperature was 1350°C, there were a lot of holes in the surface, size of grain was big and the grains were nonuniform, which due to ceramics forming liquid in sintering process and the grains anomaly grew up [9,10].
There were a lot of big holes in the fracture surface, the melting phenomenon was clearly existed in grain boundary.
Acknowledgment This research was supported by the Fundamental Research Funds for the Central Universities under grant number 2012067 , and the New Star Technology Plan of Beijing, Grant No. 2007A080.

FeNi binary system, which is a base for a number of constructional and magnetic materials, is one of the most minutely investigated systems.
Observed effect of the exposure duration may be associated with the particularities of structure given to an alloy while severe deformation produced by mechanical alloying: nanograin size, high strengths, grain boundaries etc. are the main factors responsible for reduction of martensitic temperature.
X-ray diffraction patterns of (a) as milled and (b) heated to 830 0C with no exposure Fe86Ni14 powders strength of the initial phase, which is a function of the grain size of initial γ-phase [17].
Because in the studied samples an amount of residual austenite phase is less than 10 vol. %, it is not possible to estimate the grain size of this phase reliably.
Moreover, as it was shown recently for MA Fe-Ni-Mn alloys [18], increase in annealing duration for such materials results in the decrease in the grain size; probably it is associated with the dissection of the initial austenite grains by growing non-equiaxed grains of martensite.

The electron-backscattering diffraction (EBSD) studies on AA2024-T351 alloys indicate that these grains in the nugget region are composed of high angle grain boundaries which indicate a dynamic recrystallization type origin [14].
It was attributed to the large number of intergranular facets.
Wang et al [24] studied the fatigue crack growth behavior of ultrafine grained AA2024 plates after friction stir welding.
It was also observed that slow fatigue crack growth in nugget zone was due to fine grain size [29].
Friction stir welding is a very multifarious process that includes a number of diverse physical phenomena.

On the basis of a large number of literature research, this paper summarizes the research history and current situation of the deep-water fan.
The vertical stacking patterns also change from the bottom of the erosion channel with coarse sand to small-scale relatively fine-grained levee channels.
When the gravity flow with a high speed burst the levee of middle fan, the fine-grained sediments get over the levees and develop the overbank sediments along the both sides of channels.
Big ripples are developed in the fine-grained sediments.
Levee and overbank sediments generally are fine-grained sediments.

The vanadium titanium magnetite tailings of Chengde area comprehensive recycling situation and development trend Liu Shu-xian1,a, Wei Juncong2,b, Wei Shaobo1 ,NieYi-miao1 1College of Mining Engineering, Hebei united university, Hebei Tangshan, 063009 2School of materials science and Engineering, Hebei united university, Hebei Tangshan, 063009 a liushuxian1970@163.com,b tttwjc@126.com Keywords: vanadium titanium magnetite tailings, TiO2 grade ,comprehensive recovery Abstract: Summarized the siutuation of the vanadium titanium magnetite tailings recycling in Chengde, TiO2 in ilmenite tailings grade almost more than 2%, caused by TiO2 resources waste, put forward by gravity separation, magnetic separation,and flotation combined process method for titanium iron ore tailings reelection, and put forward the technological process selection by reducing the grinding fineness, increasing number of handpick and scavenging, adopt combination process and increasing flotation process to increase
Hook tree mountain by process mineralogy research, such as mineral composition of the titanium iron ore is complex, main mineral ilmenite, titanium magnetite, limonite, hematite, pyrite and chlorite, plagioclase and pyroxene, etc; Ore fine disseminated extent relatively, low graded monomer dissociation degree + 0.25 mm. , graded + 0.074 mm high intensity magnetic separation and spiral - electrical ore dressing process, 0.074 mm fine grained level using magnetic separation - flotation process, the results show that the ore grade of TiO2 in 8.25% cases, full of coarse grained titanium concentrate grade of 46.84%, recovery 40.59%, tailings grade is 5.28%; Coarse grained titanium concentrate grade of 47.26% and recovery rate 41.06%, the tailing grade was 5.24%, in addition to the titanium content is 31.38% (after joining spiral mill tailings and tailings electricity) products into the flotation of fine grained operation recovery of fine ilmenite.

For polycrystalline alloys in general [16], and titanium alloys in particular [11, 17], the propensity for twinning increases with increasing grain size.
In small grained alloys, dislocation pile-ups of necessary length for twin nucleation are difficult to generate and so therefore leads to a higher resistance to twinning.
However, the total number of twins per unit length was found to increase with an increase in strain rate.
In all cases, the total number of grains twinned and the twin volume fraction in the grains where twins were found was the same.
Acknowledgments This study is being funded by the National Science Foundation under award number DMR0906994.

A large number of studies have shown that the lamellar structure and the basket weave structure have good creep property.
A number of dislocations formed in α phase, and the dislocation density in matrix increased.
It can be seen from the images of TEM that silicide is formed at α crystal and grain boundary.
During the long-term thermal exposure at 650 °C, silicide is precipitated in the α/β boundary and α grain, which hinders the slipping of dislocation and grain boundary.
Distribution characteristics of in-grain misorientation axes in cold-rolled commercially pure titanium and their correlation with active slip modes Metal.

However, directly transferring information gained in this simple situation to that of embedded grains in a transforming polycrystal is likely to be a very crude simplification.
Strain compatibility at grain boundaries and redistribution of stress among grains of transforming polycrystal may impose very strong obstacle for the transformation in polycrystalline state [2].
Average grain sizes obtained by optical microscopy is about d1 = 100 µm (Fig. 2) for the flat sample and d2 = 150 µm for the cylindrical one.
Therewith the number of grains in the gauge volume was sufficiently high in order to get representative measurements.
Etude de la transformation martensitique d'un alliage à mémoire de forme Cu-Al-Be à grains fins par rayons X et neutrons.

The samples were referred to as samples S300, S400, S500 and S600 where the numbers indicated the annealing temperature.
However, as the anneal temperature increases to 600 °C, the intensity of (100), (002) and (101) decrease indicates that the crystallinity of each grain becomes poor.
Increase in nuclei sites at high annealing temperature was due to Ostwald ripening phenomena where larger grains formed at the expense of smaller grains.
Thus, coalescence between smaller grains occur leads to formation of larger grains as the structure tries to lower its overall surface energy [4-6].
This result is in agreement with Malek et al. [8] that at high annealing temperature increases the surface energy of smaller grains and by diffuse smaller grains into larger grains to achieve lower surface energy in film structure.