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Despite these superior characteristic, quite number of researcher investigate the changes of this alloy after undergone die attach and wirebond process but mainly only focus on the surface area.
Grain size was calculated according to Scherrer’s equation.
The reason is due to larger grain size.
Tensile strength of copper alloy lead frames with smaller grain size is higher than the bigger grain size.
These features were due to larger grain size and lower dislocation density of defect group.

The grain growth of metallic iron was investigated in detail.
As the reduction time elongated, the small grain of metallic iron gathered toward the larger one and grew up.
The metallic iron existed in the reduction products in the form of larger grains of metallic iron.
At the same time, it could be seen that the number of metallic iron particles of small size was more, which indicated that grain of metallic iron was in the growth stage, only part growing faster iron particles became lager one.
After restored 50min, metallic iron particles grew more uniform, existing in the form of larger grains of metallic iron.

Grain size reduction is obvious.
The conclusions based on HRTEM studies of wetted grain boundaries suggest that the growth is limited by the sparse number of surface ledges or grain boundary dislocations that serve as attachment sites.
Such a roughening effect is equivalent to decrease of edge energy, so that the number of grains which can grow increases rapidly.
The numbers in the names of the specimens denote the molar ratio CaO/SiO2 (e.g.
Acknowledgement The support of this work by the Marie Curie Fellowship under contract number HPMF-CT2002-01878, the Slovak National Grant Agency under the contract N o 2/6181/26, and NATO SfP 981770 is gratefully acknowledged.

However, their applications are limited by a number of undesirable attributes.
A number of techniques have been developed to realize such a microstructure [3].
When cast near the liquidus, the grains became rosette or rosette-like.
The microstructure cast at 720°C was considerably different from that of AZ91D because of heterogeneous nucleation due to Zr, and consisted of irregular cellular or rosette grains with grain sizes of ~40-70 µm.
When cast at the liquidus temperature (629°C), the primary grains were all highly globular; most grains were 10-20 µm in size.

The unit of hardness given by the test is known as the Vickers Pyramid Number (HV).
The hardness number is determined by the load over the surface area of the indentation and not the area normal to the force, and is therefore not a pressure.
There are generally accepted that the high thermal expansion anisotropy exhibited by alumina causes stresses across the grain boundaries with increasing grain size and promote grain boundary micro cracking [15-16].
The smaller grain sizes and microwave radiation enhances energy distributions produces more thermal mismatch at the grains and grain-grain boundary interface may responsible.
Freiman, Grain-Size Dependence of Fracture Energy in Ceramics, J.

However, only a limited number of studies on the Kapitza resistance of grain boundaries have been reported [7, 8].
Yang et al. also studied the grain size effect and estimated the Kapitza resistance of grain boundaries in nanocrystalline YSZ.
Due to the similarity in transport mechanism, the classic Wiedemann-Franz law states that in pure polycrystalline metals, the following relationship holds: CWFL = κ / σT. (1) where CWFL ≈ 2.44×10-8 WΩ/K2 is known as the Lorenz number, κ is the thermal conductivity of a metal, σ is the electrical conductivity of the metal and T is the temperature.
In contrast to the large grains shown in Fig. 1, TEM micrographs of nanocrystalline nickel in Fig. 2 showed very small grains.
In nickel, thermal conductivity decreases with decreasing grain size while electrical resistivity increases over the same grain size range.

Research shows that the addition of rare earth elements to gold can refine the grains.
The oxides are dissolved out on the grains boundaries during annealing and inhibit the growth of the grains, therefore improving the strength of pure gold[7].
It was approximately directly proportional to the ratio of the numbers of gold and solute atoms at a particular weight percentage.
They increased the undercooling of metals on the crystallisation frontier, the nucleation rate at any given time, and the number of grains formed during solidification.
Owing to the deformation strengthening being primarily caused by the obstacles posed by the grain boundaries to dislocation slip, the small grain size and large amount of grains boundaries in modified pure gold intensified the hardening effect.

TNTZ, which was subjected to aging treatment at 723 K for 259.2 ks in vacuum followed by water quenching, subjected to HPT processing at rotation numbers (N) of 1 to 20 under a pressure of around 1.25 GPa at room temperature.
The materials composed of nanosized grains with high angle grain boundaries exhibit better mechanical properties and higher hardness values as compared to coarse–grained materials.
In this study, the grain size, namely grain diameter for TNTZAHPT was measured quantitatively using TEM bright field images.
As similar to TNTZHPT, the non-etched band of TNTZAHPT is thinner at low rotation numbers and in the central regions.
The thickness of the non-etched band increases with the equivalent strain (εeq) as a function of the number of rotations (N) and the distance from the center. 3.

The parameter X denotes the number of bridging anions (Si-O-Si, Si-O-Al, Si-N-Si, Si-N-Al) per network forming tetrahedron, for example [SiO4], [AlO4] or [SiO3N].
Table 1: Compositions of the grain boundary phases of all Si3N4 materials after sintering calculated with respect to the mass content of the grain boundaries Compositions of the grain boundary phases calculated from the oxygen distributions in the sintered ceramics [X].
Time / h 0 100 200 300 400 500 Thickness of corroded layer / µm 0 200 400 600 800 KORSiN 4 KORSiN 2 KORSiN 8 KORSiN 9 KORSiN 6 KORSiN 7 a) Number of bridging anions per network tetrahedron / X 1,21,62,02,42,8 Linear rate of corrosion / µm h-1 0 5 10 15 20 25 R 2=0.99 b) Figure 3 a) Corrosion kinetics of Si3N4-ceramics containing different amounts of silica in the grain boundary phase in 1N H2SO4 at 90°C b) Correlation of the initial linear corrosion rates of the corrosion kinetics with the X-Parameter (number of bridging anions per network forming tetrahedron).
In Figure 5b the calculated rate constants are correlated with the X-parameter, denoting also in the glass structures the number of the network forming anions per network forming tetrahedron.
The number of bridging anions per network forming tetrahedron can be rated as an appropriate parameter to correlate the dissolution rates of the Si3N4-ceramics i.e. the grain boundary phases and the YSiAlON-glasses with the structure of the glass-network (Figure 3b and 5b).

Denomination Magnetism Aided Machining (MAM) comprises a number of relatively new industrial machining processes (mainly finishing and surface improving) developed presently, too.
v f \ Al2O3+Fe grains grains a) b) Pole Workpiece Al2O3+Fe grains Fig. 1.
The consequences based on the experimental results are: • The natural (mined) Al2O3+Fe grains have sharper cutting edges than the TiC+Fe grains produced by sintering, thus the material removal rate (MRR) is higher using the former type of grains
For finishing cuts finer grains (Wz = 100…300 μm) are recommended
The grist or flour fills the cavities of the grains, and this way the grains glide over the fine surfaces of the workpieces without scratching them while the sharp burrs will be removed.