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Introduction A major number of electronic packaging industries around the world have continued to research the lead-free soldering technology, and so the use of lead-free solders for electrical products has been advancing.
White region which was β-Sn grain was surrounded by gray region which was eutectic structure.
In the case of Sn-3.5Ag-1.0Cu-0.2Mg solder and Sn-3.5Ag-1.0Cu-0.4Mg solder, the grain size of the white region was similar with that in the case of Sn-3.5Ag-1.0Cu solder.
The number of IMCs in the Sn-3.5Ag-1.0Cu-0.4Mg solder is more than that in the Sn-3.5Ag-1.0Cu-0.2Mg.
(2) In the case of Sn-3.5Ag-1.0Cu-0.2Mg solder and Sn-3.5Ag-1.0Cu-0.4Mg solder, the size of β-Sn grain was similar with that in the case of Sn-3.5Ag-1.0Cu solder.

The main material in drill is cemented carbide composed of ultra micro grains.
Figure 5 shows a result that the chips generated under MQL are black compact shape grains (see fig. 5(a)) and those under emulsion (see fig. 5(b)) are shiny elongated shape grains.
Table 4 Cutting conditions Drill size Work material Cutting speed [m/min] Feed rate [mm/rev] Cutting depth [mm] Coolant Guid e hole [φ] Guide depth [mm] φ 6 Carbon steel S48C 80 0.2 106 Emulsion MQL 6.05 10 � ��� ��� ��� ��� ���� ���������@ 04 
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��Emulsion Number of drilled holes Table 5 Cutting conditions Drill size [mm] Work material Feed rate [mm/min] Cutting depth [mm] Coolant 6 Carbon Steel S45C 0.12 18 Emulsion MQL Fig.8 Comparison of drilled holes under MQL and emulsion In case of out side MQL, the tool life of a drill can be improved at the only case of what a lubricant is supplied from hole to hole.
It is evident that the tool life and wear-resistance of drills are markedly improved due to the proposed multilayer TiAlN coating on the substrates made of micro grain materials and polishing techniques. 2.
Yamamoto: Mechanical Engineering Vol.57, 9(2005), pp40-42 ���� ���� ��� ��� ���� ���� ���� ���� ���� ���� 0 2000 4000 6000 8000 10000 50 80 120 150 180 Cutting speed �m/min� Numbers of drilled holes emulsion MQL

It was founded that the grains in Al-1.9Si-1.32Mg-0.40Mn casting ingot was coarse and no obvious defects such as porosity and loose; There existed fine equiaxed grains at top layer, and columnar crystal region grown vertical to the die wall in the middle region, and equiaxed crystal region in the core.
It was founded that the grains appeared rosette morphology and its size was about 200 um.
There emerged some deep corrosion pits on the surface of Al-1.9Si-1.32Mg-0.40Mn casting ingot attached by plenty of white grains.
Al-13Si casting ingot sample had been covered entirely by a large number of white attachments, on which could not found any Al-substrate morphology.
Al-18Si-0.01%P possessed a large number of block primary silicon, eutectic silicon phase and a little of white α-Al phase

Thermal fatigue tests were held in a high frequency induction furnace, which was contributed by Inductoheat Company and rebuilt in our laboratory, possessing functions such as automatic controlling of heating, cooling and recording the cycle number.
However, microstructure is uneven, and coarse eutectic carbides and composition segregation exist in the annealed 4Cr5MoSiV1 steel, and the secondary carbides gathered at the grain boundaries, and chain-like distribute in the locally area, as shown in Fig.3.
Second, eutectic carbides and grain boundary secondary carbides both deteriorated the impact toughness to a great extent.
Eutectic carbides particles embedded on the equiaxed ferrite matrix, and grain boundary secondary carbides existed at some locations of 4Cr5MoSiV1 steel as shown in Fig. 3a.
The thermal fatigue cracks usually expand through the grain and other places which has relatively low strength and bad toughness.

Intergranular corrosion (IGC), one of common failure modes in nuclear power plants, is a local damage corrosion which generates and propagates along or next to the grain boundary in particular corrosion environment [1].
A Large number of welds exist in nuclear devices during the manufacturing process.
The three zones sufferes IGC to a certain extent and a few of grains peel off in BM and HAZ, i.e. the black spots in Fig.3(a) and Fig.3(b).
The grain boundary suffers further corrosion and an increasing number of grains peel off.

As shown in the Table, the Ms temperature is lowered as the number of thermal cycles is increased.
Amount of ε martensite as a function of the number of thermal cycles in Fe-17mass%Mn alloy.� Fig. 7.
It is observed that the ε plates with only one orientation were formed in an austenite grain of the 700°C specimen, but the 1000°C specimen produced the ε plates with several different orientations in an austenite grain.
Fig. 13 shows the ε volume fraction together with the damping capacity against the thermal cycle number.
(2) The ε martensite volume fraction at room temperature increases with increasing the thermal cycle number.

As-ground Al2O3 blocks were used for a more limited number of joints.
A limited number of Al2O3 joints and all ZTA joints were also prepared at 1400°C in a vacuum furnace using a 6.7-kPa bonding pressure.
GS denotes the grain size assumed in the modeling.
Grain size refinement, grain growth, grain-boundary penetration by liquid films, and other related phenomena may provide avenues for accelerating liquid disappearance, and also engineering interlayer systems that alter the fracture path.
At present, the number of ceramic and interlayers systems that have been explored is very limited.

The grain size of nanocrystalline TiC is under 100 nm, which makes it capable of replacing micron TiC powders as raw materials, reducing sintering temperature, and improving sintering performance.
A number of methods to synthesize nanocrystalline TiC powders have been proposed, such as hydrogen plasma [6], mechanical alloying [7], microwave carbothermal reduction (CR) [8], petroleum coke salt bath [9], and Mg-thermal reduction [10].
Pre-activation of these materials with mechanical ball milling reduces the temperature of TiO2 CR reaction and thus leads to the synthesis of ultrafine TiC powders with nano grain size.
This result indicated that mechanical ball milling decreased the TiO2 grain size because of increased internal stress.
A single TiC with a grain size of about 25 nm was synthesized at 1300 °C.

The Taylor factor of each grain with orientation g can be calculated from the slip rates and von Mises' equivalent strain rate ( 2:/3 vMε = εε & && ) 1 sN g s vM M γ ε= = ∑ & & (4) Incorporation of all new grain orientations calculated from lattice spins and the initial grain orientations can lead to the crystallographic texture or orientation distribution function f(g) after each strain increment.
The drawback of this model is that it cannot guarantee the stress equilibrium at grain boundaries.
The Alamel model differs from Lamel model in that the Alamel model can incorporate real or more realistic microstructure of the grain boundaries, while the Lamel model assumes the grain boundaries are always parallel to the RD×TD plane of rolling.
The number of increments is chosen to be forty, which leads to a total shear strain of -2.0.
As for the Alamel model, the microstructure of original rolling grain boundaries must be considered.

The fractal dimension are volatile, the fractal dimension reach the maximum at 200 ℃, it can be inferred that the granite rock burst the most energy consumption at 200 ℃; (2) From 200℃ to 800℃, the cracks transform from stepped cleavage, intergranular fracture gradually to grain crushing, transgranular cracking damage with the rise of temperature.
The variation of the fractal dimension with the stress level in each structured specimens as well as the variation of self-similarity range with lithology and grain size were analyzed.
Given to the size of the box, then count the total number of boxes N that can cover the cracks totally .
Assuming the lattice is used when k-step, the required number of boxes is, then the box dimension is calculated as following: (1) is side of the lattice used to cover the rock cracks ,is the number of lattice intersected with the fractal set F.
Calculated steps are importing images, image processing, and cut the computational domain, statistics box cover number, calculated box dimension, export the results.