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C in Fig.1c) is still rod-like distribution along the grain boundary, has not changed on the morphology during aging.
As shown in Fig.1d, after artificial aging, a large number of precipitates were precipitated in the crystals (shown in black and gray hue).
In this paper, on the one hand, a large number of precipitates would pin partial dislocations during aging treatment, but in the process of quenching and aging could produce a large number of newly dislocations and interfaces, which "make up" the dislocation damping performance loss caused by precipitate pinning.
Although the grain growth will occur in the aging process, but the modification additions can hinder the grain growth.
However, adding Sb can refine grains and hinder the grain growth and the reduce of equiaxed degrees during aging, which conducive to the non-elastic viscous movement of grain interface.

Since the initial positions of particles can significantly influence the simulations results, a random, isotropic distribution of grains with realistic coordination number and radial distribution function is used.
The initial density is set to 60% and the initial coordination number is 6.1.
Voigt gives an upper-bound for G/K of 0.6 that is independent from the coordination number [22].
The increase in G/K if grain rearrangements are possible is an indicator that because of an increasing coordination number the grains become more stable against shearing.
This coordination number dependence is also captured in the self-consistent estimate, which gives a G/K ratio of 0.27 for a bcc structure with a coordination number Z = 8 [22].

Where, is the average particle diameter. is the total area of particles, and is the total number of particles.
As shown in Fig.2(c), while the pouring temperature is 600℃, rosette non-dentritic grains are rounded up to uniformly distributed grained and spherical grains with the average diameter of 49.9μm and shape coefficient of 0.71.
Therefore increase of nucleation and refining of the grains were intensified.
The most sensitive areas such as dendrite arms of dendritic particles were broken and a number of fine grain formed[15].
(2)Vibration can refine the grains of the ZAlSi9Mg alloy.

The existence of Ba-b-Al2O3 phase as well as low sintering temperature and short holding time during reactive sintering inhibit grain growth and thus result in small grain sizes of the Al2O3 matrix.
Bright regions correspond to high atomic numbers (Ba), whereas dark regions correspond to lower atomic number (Al).
At 1400oC, the Al2O3 matrix exhibited fine grains and their average size was 0.78 mm.
With the increase in sintering temperature, grain growth occurs.
As shown in Fig. 6(b), the average grain size of the Al2O3 matrix attained 1.49 mm at 1500°C.

In the machining process, as the silicon grains in the alloy affect tool wear greatly, the tool materials should have high performance.
Then, the silicon grain contacted with the tool tip.
Additionally, the rigid silicon grains in hardened layer can also induce micro breakage on the cutting edge.
Contrasted with cutting common metals, the hard silicon grains in the Si-Al alloys make the friction between the workpiece and the clearance face worse.
The micro pectinate grooves on the clearance face were mechanical wear produced by silicon grains and other hard grains in Si-Al alloy.

For the last decade, there have been a number of studies aimed at understanding the kinetics of IGC [3] and exfoliation corrosion [4].
Increasing the 'strength' of a texture means there is a high tendency for grains to orientate themselves with a similar crystallographic orientation as other grains, as opposed to 'weak' texture where the grains orientate themselves more randomly.
A strong texture results in low misorientation angles between adjacent grains.
Therefore, the tendency for the corrosion path to branch off a susceptible high-angle boundary will be reduced if the number of low-angle boundaries is increased, making IGC more directional.
As mentioned above grains will develop a preferred distribution of orientations.

To describe the corrosion morphology, two parameters were statistically determined: the number of corrosion defects propagating in the L direction and observed for a given distance in the ST direction (density of corrosion defects) and the average depth of corrosion defects in the L direction.
Taking into account the cumulated length of corroded surface observed in the ST direction, i.e. 80 mm, and the grain size in this direction (about 60 μm), almost 1000 grain boundaries and grains were observed for each test.
When the NHT samples were aged, the density and size of T1 precipitates in the grain boundaries increased but numerous T1 precipitates also formed inside the grains.
The galvanic coupling effect between the grains and the grain boundaries was reduced so that intergranular corrosion did not occur.
Fig. 3c suggested that the branching could be attributed to both an extent of the corrosion to a larger number of grain boundaries but also to the dissolution of subgrain boundaries.

Some grains were not smashed thoroughly, but curved and necked down, and a large of grains with fine, homogeneous and spheroids presented at 570°C (Fig.1b).
When the stirring speed was slower, the grains became larger.
When the stirring temperature was too lower, the grains grew up and got together, which made the grains coarsening and the mechanical properties reducing.
The smaller the grain size, the larger the area of grain boundary, the greater the numbers of different orientation around each grain and the plastic deformation resistance were.
The deformation could disperse into more grains.

Ssubgrain structure, partially recrystallized structure and fully recrystallized structure are evolved after different numbers of ECAP passes.
Volume fraction of true grains is relatively low (~13 pct).
Grains and (sub)grains exhibit essentially equiaxed shape.
The fraction of recrystallized grains with an average size of ~550 nm is ~76 pct.
UTS decreases under ECAP with small number of passes and attains initial value after 8 passes.

With removal from the active zone of deformation the grain size increases, and microhardness decreases.
At the same time these alloys possess a number of advantages the major of which is an opened single-phase α-area along with an economy of cobalt.
In the top part of the samples, near to fixed head, the of grain size was maximum and in the middle part it has an average value.
The fraction of special grain boundaries sharply decreased and the fraction of low angle boundaries considerably rose.
It was shown that application of the method of complex loading allows obtaining gradient microstructure with minimum grain size near to mobile head and a constant increase in a grain size along the vertical axis of the sample. 2.