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The results depict that at 300 °C the number of contact peaks of the micro roughness increases with the applied normal force incrementing the contact area and thus the friction force.
At 300 °C, the shear zone (h=450 μm) consists of stretched grains due to high shear deformation.
Moreover, toward the specimen’s center the grains appear with their original shape.
New small grains were observed at 350 °C (Fig. 8a), and some grain growth was detected at 500 °C (Fig. 8b).
When the precipitation number is reduced, the dislocations move with less resistance and consequently the hardness and flow stress are reduced.

The base material has elongated grains, is a typical rolling microstructure.
The grains size of HAZ is wider than that of base material.
The fusion line is the dividing ling between the base metal and the weld pool, which appear a narrow gap with tiny grains.
With respect to the base material and single-wire MIG welding (Fig.1a), the grain sizes of weld grow bigger during the weld thermal cycle (Fig.1c).
A large number of dimples can be seen in short break area, and a small amount of fatigue striation is found.

In FSW, the material undergoes intense plastic deformation at elevated temperature, resulting in generation of smaller and finer grain size [1,2,16].
So it optimized to a certain number, where the holes in the weld becomes tightness [4].
A box-behnken design has smaller number of runs.
The UFSW joint has a fine grained microstructure without S-line defect, a typically distinct boundary between the weld nugget zone and the thermo mechanically affected zone and a narrow heat affected zone.
Three different micro structural zones have been identified in friction stir weld, i.e., nugget region, characterized by fine and equiaxed recrystallized grains, thermo mechanically affected region, characterized by deformed and uncrystallized grains, and heat affected region, characterized by precipitate coarsening.

A grain size distribution test of the soil was also performed to show the type and gradation of the soil.
The grain size distribution of the soil, which is used for the unfired soil lime bricks, spans from clay to medium grained sands. 60% of the soil, by mass, consists of fine to medium grained sands.
In the previous study [7] the same type of mixture and number of brick, were also employed for testing plain bricks (without any fiber addition) and bricks containing non uniform fibers.
Even though the percentage of mass of coconut fibers are the same (4%) between the uniform and non-uniform fibers, but at early age as the soil lime reaction just takes place a more number of fiber strand as contribute by the non-uniform fibers inside the brick might give advantage to the distribution of vertical force.

There are a number of research institutions to improve the diffusion of silicon infiltration method, by adding alloying elements and applying insulating film to improve performance and reduce high-frequency noise.
Using this process could obtain a fine grain and raises attention.
Fast-setting usually consists of high silicon steel with columnar grains and equiaxed grain size of 10μm, its magnetic properties are: coercive force Hc is 48.5A/m, the hysteresis loss is 1.24W/kg.
The method is laminated to a number of blocks of high silicon steel sheet as a core material coated with another coating material around them, and then subjected to hot rolling.
Because the hot rolled grain structure of coarse columnar form banded structure, good ductility cladding layer so hot rolled silicon steel sheet of high elongation at low temperatures is greater than 5%, and it is good to improve ductility in cold rolling process.

Introduction As magnesium (Mg) and its alloys possess many advantageous properties, they have thus been found great importance in a number of applications such as manufacturing of automobile and 3C parts, aerospace components etc.
There are a large number of coating technologies, divided two types of protective barrier, available for protecting Mg and its alloys.
For sample, the grains of Mg alloy without plasma treatment and TMS interfacial film can be seen clearly from Fig.1a, A0 with E-coat only.
The grain boundary had a little extrude compared to grain, thus more Mg17Al12 phase, which has better corrosion resistance than matrix α-Mg in grain, appeared at boundary when Mg alloy was not protected without any coating.

Cracks were observed in certain areas with the formation of stray grains.
The coatings should be single crystal to eliminate the diffusion short circuit through grain boundaries.
The substrates are formed by equiaxial alpha phase grains (pure titanium) or alpha-beta phase (Ti64 alloy).
The lower wear loss in case of Ti64 at lower number of cycles (9.72 x 105) is probably due to the hardness difference in both materials.
For samples tested at high number of cycles (7.76 x 106 cycles), the wear loss improvement was almost 10-fold for Ti and 100-fold for Ti64 bearings.

The composite strengthening mechanism by the addition of SiC can be explained through a number of mechanisms, among others, strengthening and grain refinement [2].
Furthermore, the increase in ductility can be achieved through a number of ways related to homogenous distribution of particles, particle size (<10 µm), uniformed distribution of particle size, high strength of interface, and ductility of the matrix [12].
At low concentration (0.1 wt.%), the grain size is larger than that of pure A356.
However, at higher concentration, the grain size is getting smaller until an optimum concentration of 0.25 wt.% after which the grain size starts to grow bigger.

The upper shear box is composed of 10 overlaying rings, which is 30mm high and numbered from top to bottom.
Test material.The test material is gravelly soil selected from retaining wall site in Chongqing of China, because the largest grain size in the field is greater than 60 mm, in situ grain size distribution need be modified to fit in the test apparatus, which is 60 mm in diameter.
The simulation curve of grain size distribution using the Equivalent Weight Replacement method is shown in Figure 1.
Grain size distribution curves of in situ and reconstituted specimen Fig. 2.
Vertical load kPa Pulling rate mm/min Number of geo-band Gravelly soil Water content w (％) Dry density (g/m3) 1 300 0.3 5 3.7 2.24 2 400 0.3 5 3.7 2.24 3 500 0.3 3 3.7 2.24 4 300 0.3 3 4.7 2.24 5 400 0.3 3 4.7 2.24 6 500 0.3 3 4.7 2.24 7 300 0.3 3 5.7 2.24 8 400 0.3 3 5.7 2.24 9 500 0.3 3 5.7 2.24 Test Result Analysis Calculation formula.The interface pulling friction strength is calculated as the formula below: (1) Where is the pulling friction strength; is the total horizontal tension at peak value; B, L is the buried width and length in the soil.

Role of Rare Earth Elements in Magnesium Alloy The alloying element is chosen based on the number of required properties.
Several alloying additives should be used to increase the number of precipitates and by forming complex precipitates improve the properties of the precipitate.
The elements Sc, Y, La and the lathanides as well as Nd, Tb, Er, Dy and Gd, with Zr as grain refiner, form the basis for the development of creep resistant alloys.
Stanford et al [22] reported that at 450˚C, extruded Mg-La alloy formed a new texture component with much fine grain size.
As a result of this fined grains the ductility were improved.