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Un-grain refined ingots of the alloy with the chemical compositions of Table 1 were used.
Thus, longer treatment time lead to larger globule sizes, since fewer number of aluminum fragments survive and participate in solid phase nucleation.
It is obvious that the untreated billet shows inappropriate microstructure for thixocasting with large dendritic grains as compared to the UST-treated samples shown in Fig. 5.
In addition, die filling was inferior to the ultrasonic treated billets, since the large dendritic grains cause poor filling in the semisolid state due to solid bridging in the gating and die thin sections.
The Fe-intermetallic particles appeared in plate-like form in the as-cast billets (arrowed in Fig. 6(a)), and a considerable number of these particles were in fine compacted form in the thixocast parts, as arrowed in Fig. 6(b).

A large number of slag is piled, which is not only a waste of resources, but also pollutes to the environment[2].
Through thermodynamic theoretical analysis and a large number of calculations, firstly the mixture calculation of principal component was completed.
Table 2 Effect of adhesive (PVA) on press forming Number PVA(wt./%) Addition(wt./%) Effect 1 2% 5% of raw material Could not be pressed into bricks 2 2% 10% of raw material Could not be pressed into bricks 3 5% 5% of raw material Could be pressed into bricks, but intensity was low, and fragile 4 5% 10% of raw material Fragile, and intensity was low As was shown in Table 2, the simple change in the amount of added PVA adhesive could not solve the pressing problems.
Because first firing had been formed parts of the TiN crystal phase, although not very obvious, but they would be the core of TiN grain growth when the twice firing, which could help TiN crystals grow.
The XRD results indicated that first firing had been formed parts of the TiN crystal phase, which would be the core of TiN grain growth when the twice firing and could help TiN crystals grow. 3.

Once again, all these diagnosis methods have their own disadvantages, for example, the sample preparation for optical microscopy is very delicate and time consuming and a large number of gel and cracking must be formed for good examination; for SEM-SE, the observation of a fracture surface is not reliable.
The grey level of BSE image is directly proportional to the backscattered coefficient η, which is related to the atomic number Z by the empirical equation [6, 7]: (1) Where a0, a1, a2 are coefficients, which depend on the parameters during image acquisition, such as the accelerating voltage.
Accordingly, the higher the average atomic number, the brighter is in the backscattered image.
Fig. 4 shows the mapping of concrete, presenting the reaction of fine dolomite grain with alkali.
Hydrotalcite has a fibrous structure, which is filled with the original dolomite grain.

Therefore, a balanced proportion of fine grains is a key element in mix design
ACBFS has an irregular grain shape with sharp edges.
Figure 1 shows the nature of ACBFSA grains at the micro-scale compared to gravel and crushed natural aggregate grains.
The gravel grain is virtually pore-free and with a glossy surface, while the crushed grain contains a negligible number of pores (colored dots) and an irregular shape and a rough surface.
The values are higher than most published requirements and are due to the considerable number of pores in the grains

The term in Eq.3 including the permeability is only used below a defined packing fraction for the solid grains.
For the solid free grain (slurry) regime, following [3], a similar equation like Eq.3 may be defined and simplified by neglecting the inertia term (solid grains are instantaneous accelerated by the liquid), and using that the solid particles are completely surrounded by liquid with pressure pl we end up with the following solid momentum conservation equation: (4) where D is a drag term for the free grain regime.
The radiosity equation that is solved for each element surface i is: (8) where B is the radiosity, Fij is the view factor that defines the fraction of radiation leaving surface i which is intercepted by surface j, σ is the Stefan-Boltzman constant and n is the number of surfaces making up the enclosure.
In order to utilize this processing power efficiently we have chosen to use the OpenMP programming model for a number of reasons: Programming is made via pragmas which are special comments that may be interpreted by the Fortran compiler.
The speedup of the assembly loop scales very well with the number of processing units, while the overhead with administration/duplication of memory diminishes the overall speedup some, e.g. for 8 processing units we might expect a speedup of 7 for the assembly process.

After the surface crack becomes visible, the number of impact blows is recorded.
The filler of the mix is silica sand with minimum grain size of 80 micrometers and maximum grain size of 200 micrometers.
Normal distributions of number of impact blows for the six groups of specimens.
Retained number of impact blows of the six RPC groups at age of 28 days.
This number was approximately twice that of SF6 and H-SF groups.

Finally cut the foamed bamboo fiber productions into small grains.
Test the static buffer characteristics of the small grains, and then F-X, σ -ε, C-ε curves could be recorded.
The mixture proportioning of two blowing agent 1:1 1:2 1:3 The amount of blowing agent reaction AC and inorganic foaming agent reaction completely AC and inorganic foaming agent reaction completely AC and inorganic foaming agent reaction completely The quality of cell Delicate, less cell dense Coarser cell sizes Coarse cell, the small number of high expansion rate Cross-sectional Serious fiber stick together Fiber interwoven distinctive aperture Fiber interwoven distinctive aperture Table 2 The impact of the different complex ratio of the AC blowing agent and inorganic blowing agent for foam products The static compression characteristics test Based on GB8168 "The static compression test method of cushioning material for packaging" , placing a cushioning material has been cut into small particles in the constant temperature and humidity tank with at a temperature of 20 ° C, humidity of 65% , Test will begin after 24h the pretreatment [6].The F-X curves is shown in Fig

During this treatment, Ω phase and phase become coarsening to some extent, besides, their number densities decrease too.
We attribute this to the occurrence of the coarse equilibrium phases in grain boundary and the widening of the precipitation free zone (PFZ), as shown in Fig. 6
After long time exposure, i.e., 1000 h, coarse equilibrium phases or small impurity particles were found segregated toward the grain boundaries, making them discontinuous.
When a high stress was loaded, grain boundaries or interfaces between the matrix and small inclusions are separated, and then microvoids formed.
The decrease of strengthening phase in number density and volume fraction caused the descent of strengths of the experimental alloy.

However, neither of these methods have yet been fully optimized and a number of issues remain.
EBSD analysis (Fig. 3c) reveals that the severe deformation leads to an extremely fine grain structure within the weld deformation zone of ~ 1 -3µm.
Weld formation in FSSW and USW; macroscopic sections showing the progressive stages of weld development for (a) FSSW, and (b) USW, and EBSD analysis of the grain structures within the deformation zones, (c) FSSW for the 0.4 sec weld and (b) USW from a 0.25 Sec weld.
The magnified EBSD maps are the 3 numbered regions highlighted.
In FSSW there is a strain gradient decreasing from the tool surface, which results in an approximately bowl shaped ultrafine grained nugget zone.

The third method is coarse-grained molecular dynamics (CGMD), where the FE/MD coupling is based on a derivation of the physical scaling properties of the system.
To limit the number of references, only above few representative ones are listed.
Some promising models and methodologies have been presented, such as quasi-continuum method, hand-shaking region method and coarse-grained molecular dynamics method.
Coarse-grained molecular dynamics (CGMD) has been developed as a substitute for the finite elements which does not connect seamlessly to molecular dynamics in the atomic limit.
A coarse-grained mesh partitions the system into cells, and it can reproduce the results of finite elements in the limit of large element size.