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Titanium is one of the most effective grain refinement elements in aluminium alloy.
The coarse columnar grains are formed in pure Al ingot, while the fine equiaxed grains are formed in the Al ingot with low Ti content (fig.3).
There are two reasons for the grain refinement of Al ingot.
A number of TiAl3 particles could be precipitated from melt during solidification of billet, and α-Al grains can easily nucleate on the TiAl3 particles, therefore equiaxed grains can be formed.
On the other hand, the grain size of Al ingots is depending on the growing rate of the grains.

LH intentionally machines the grain cave, which has the certain angle, depth, and width etc..
The laser sculpting structure is neatly adopted for requesting terms by the number controls system.
crossing structure, the grain space is 600µm, grain width is 30µm, grain depth 5µm, crossing angle is 30e.
Comparing with the standard cylinder, the total grain let lowers 20%-25%, only the grain let of the engine oil lowers 25%-30% for the cylinder by LH.
The single sculpting design can be a grain, concave etc., and cross section of the stripe may be a circular, triangle etc., the mode of sculpting distribution may be a reticulation and a oblique grain etc..

A number of literatures reported that the introduce of ultrasonic can provide good influence to the condition of composite codeposition, promote the homogeneous dispersion of the nanoparticles in composite coatings[3,4].
In order to obtain accurate test data, the number of specimens prepared to the experiment is three, and the corrosion rate take the average.
Under the rotating of cathode, hydrogen bubble and rough grains which absorbing on the surface of rotating cathode could be cleared in time; and the continuous growth process of crystal grains could be broken easily, which is helpful to the grain refinement of the composite coating[9].
The remarkable corrosion resistance may be attributed to the denser structure and finer grains of the coating.
The crystal grain of the nanocomposite coating prepared by rotating cathode in an ultrasonic field is refined remarkablely

Table 1 Annealing conditions and grain sizes of thin pure Ti foils.
Since a single grain within the material is composed of grain interior and grain boundary, the flow stress of the material can be considered to consist of the flow stress of grain interior region and the flow stress of grain boundary region [15].
The flow stress of grain interior region is contributed by SSDs, while the flow stress of grain boundary region is contributed by both SSDs and GNDs.
Due to a smaller number of grain boundaries in the foils with larger grain size, the density of GNDs decreases with increasing grain size.
(2) The density of GNDs decreases with increasing grain size, indicating the less strain gradient of the foils with larger grain size

The surface roughness and grain size were evaluated by atomic force microscopy.
There is also a decrease in grain size (from 176 nm to 120 nm) as the bias is increased.
The decreased grain size as mentioned before is due to the increased bias voltage.
It decreased when a higher number of ions with higher energies start bombarding the surface which caused an etching-like process making the surface smoother.
Also via line profile avg. values of grain size for both the samples were obtained.

The microstructure of the No.1 and No.2 alloy both showed fully recrystallized fcc-γ grains with the average grain size of about 65 μm and 13 μm, respectively.
In this study, with primary aging temperature increasing, the size of γ′ and γ′′ phase becomes larger and the number of precipitation particle decreases, as shown in Fig. 7.
It should be noted that in the case of the element with smaller atomic number, the analysis accuracy of EDS is low, thus the quantitative composition of C may be inaccurate.
Furthermore, at lower primary aging temperature, little carbide is observed on grain boundaries and most of the grain boundaries are clean.
Furthermore, the film of continuously precipitated carbide on grain boundary could be another reason for the embrittlement of grain boundary.

One is “intragranular”grain, which exits in the alumina grain and the number is less.
The other is “intergranular”grain, which exits among the alumina grains and the number is larger
Generally, the binding force of grain boundary is weaker than grain interior, thus the cracks extended firstly along grain boundary and grains showed a tendency to focus on the crack tips.
Generally, the binding force of grain boundary is weaker than grain interior, thus the cracks extended firstly along grain boundary.
This stress field acts together with cracks, resulting in weak bits to exist in the grains and the binding force of grain boundary higher than grain interior.

A microstructure analysis of the solid shape revealed a bimodal grain distribution.
The characteristic microstructure of each region is comprised of two easily distinguishable microconstituents: fine equiaxed grains and large coarse grains elongated in the extrusion direction as shown in Fig. 1.
The relative amounts of either fine or coarse grains varied by section. 40 µm Figure 1.
Example of a microstructure comprised of both fine equiaxed and coarse grains.
A workability evaluation was performed by Rao’s research team, using the results of the compression test for number of Magnesium alloys.

For horizontal mode of settlement, there is the following formula[4]: (2) Galileo number Ga also introduced in Reynolds number Re to simplify computing drag coefficient CD and terminal settling velocity Vt[5]: (3) In formula (3), h is the dynamic viscosity of the fluid, ρf and pρ are density of fluid and particles respectively.
(14) The unified drag coefficient relationship for both platy grains and cylindrical grains can be obtained by replacing formula (12) with formula (16).
The results also show that it is not enough for describing characteristics of complex grains using only one or two shape parameters.
According to the definition of Fn and Fm, the drag coefficient relationship proposed in this paper can be used to distinguish four kinds of particles: cuboid, cylindrical rod, sheet strip and flat shape grains.
Wadell: The Coefficient of Resistance as a Function of Reynolds Number for Solids ofVarious Shapes, Journal of Franklin Institute, April 1934, 459-490Wadell

Experiments were performed on dowel-type timber connections with one, two and three slotted in steel plates under lateral loads parallel to the grain.
Test variables include the number of steel plates, the spacing of the steel plates, and the dowel diameter.
Results show that the load-carrying capacity of the dowel-type connection increased as the number and spacing of steel plates in the same thickness of timber specimens.
In order to understand the mechanical properties and failure mode of this type of connections well, four groups of 11 specimens with different numbers and the spacings of steel plates and different dowel diameters were tested.
Fig.1 Configuration of dowel-type connection with slotted in plates test Table.1 Summary of dowel-type connection test Specimen group Specimen number Number of slotted-in steel plate Dowel diameter d (mm) Steel plate dimensions l×b×h (mm) T/d t2 (mm) t1 (mm) t2/t1 A A-1 3 12 200×250×8 17.5 30 60 0.5 A-2 45 45 1.0 A-3 60 30 2.0 B B-1 3 16 13.1 30 60 0.5 B-2 45 45 1.0 B-3 60 30 2.0 C C-1 3 20 10.5 30 60 0.5 C-2 45 45 1.0 C-3 60 30 2.0 D D-1 1 12 17.5 0 100 0.0 D-2 2 100 45 2.2 Test procedure Dowel-type connections were tested in compression parallel to the grain, as shown in Fig. 3.