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LAT crack repair experimental matrix Sample Label Deposition Re-melt Spot size (mm) Powder feed rate (rpm) Gas flow rate (l/min) Bead width (mm) Bead height (mm) Number of re-melt runs Scanning speed (m/min) Deposition tracks Number of weld runs Laser power (kW) 2 mm crack size at focal length 178 mm A1 2 - - 2 1 1 4 - 10 10 1.75 - 0.58 - - 5 2 2 10 - 5 A2 1.3 - - 2.5 1 1 4 - 10 10 1.9 - 0.78 - - 2 2 2 8 - 5 A3 1.3 - - 1.5 1 1 3 - 10 10 1.8 - 0.71 - - 5 0.5 0.5 9 - 5 3 mm crack size at focal length 195 mm A4 1.3 - - 1.5 2 2 3 - 10 10 2.7 - 0.69 - - 5 0.5 0.5 9 - 5 A5 1.3 - - 2.5 2 2 4 - 10 10 2.9 - 0.8 - - 1 0.5 0.5 8 - 5 Results and Discussion A.
For A1, A3, and A4, α +β phases whose HAZ show epitaxial grains and dendritic macroscopic bands with α-grain and β-grain boundaries whose sizes reduce towards the substrate, indicative of heat flow direction, are shown in Fig. 5.
Macrographs for A1, A2, A3, A4 and A5 clads at x 1.6 magnification The FZ of A1, A3, and A4 samples are dominated by fine martensitic, Widmanstätten, basketweave structures, fine acicular grains and thick rectangular columnar prior beta grains normal to the plate from the weld top to bottom, which is typical of high-energy processes [19].

The grain size of the Ca(MoO4)x(WO4)(1-x) microcrystallines gradually increases with the increasing x (except x=0) and their agglomeration also becomes serious with x increasing.
From Fig. 4, one can see that all the as-synthesized Ca(MoO4)x(WO4)(1-x) microcrystallines are uniform spherical grains.
After the replacing by MoO42- and forming Ca(MoO4)x(WO4)(1-x) solid solution microcrystallines, the grain size of the microcrystallines decreases significantly.
These phenomena probably are owing to the lack of any stabilizing surfactants and the grains are self-assembly hierarchical structures [9].
Their grain size gradually increases with the increasing x(except x=0) and agglomeration becomes serious with x increasing..

Diatomite (upper micrograph) and (below) plus S-phase (dark grains) - after [2].
Its formation via the reaction bonded route [8] enables good combinations of hardness and toughness to be achieved (1850GPa and 5.1MPam½ respectively - the latter figure being typical of what many authors observe for α-sialon samples in the form of needle shaped grains) and many authors (see for example [9,10]) have studied the transparency of carefully prepared, fine-grained, clean grain-boundary samples of α-sialon (see Figure 3).
However, in the 1990s, increasing numbers of new structures emerged, and this has continued into the present decade.
The pairs of numbers indicate the LiAl5O8/AlN content in the strating mix (after [15]) Fig. 6.
In contrast to the number of papers that have appeared describing optical phenomena, the number interested in electronic applications is far less.

Isolated grains formed having a quasi-spherical form which have been identified as mixed magnesium and tin oxides.
SEM micrograph (see Fig. 1) and EDS spectra of the sites numbered 1 and 2.
Gaps between grains can be observed and MgO/Mg(OH)2 is detected (site marked 1 in Fig. 4).
The isolated grains formed have a quasi spherical form of about 8 µm in diameter (sites marked 2 and 3 in Fig. 4).

Using the high-temperature properties of the plasma arc to strength the metal surface, compared with conventional hardening heat treatment, heating and cooling of the plasma surface hardening process are faster and the crystalline grain is smaller, so it can remain a very high toughness and ductility under the high strength and hardness conditions [4].
In order to reduce the number of trials, we choose the orthogonal test method [5]; according to the sweep length required by the treated workpiece, we choose the nozzle’s diameter at 2.8mm to control the scanning bandwidth; working gas and shielding gas flow were set on 0.025 m3/min.
After being scan by plasma arc beam, the test specimen surface organization changed significantly, the organization grains can be greatly refined.
Using plasma arc beam scan the specimen’s surface, for the energy density of the arc beam is highly concentrated, it allows the temperature of the surface instantly reach the phase transition temperature, nearly melting temperature; due to fast heating, the larger phase transformation driving force, the pearlite is quickly converted into the austenite, while the inner temperature is still at room temperature, after taking away the arc beam, owe to the specimen's own rapid heat transfer, the scan area was cooling rapidly, the cooling rate is far faster than the transformation speed of the martensitic, austenite tiny grain had no chance to grow up, the carbon element in the cooling grain has no chanceto spread out, they achieve self-excitation cold hardening, produce detailed acicular hidden martensite.
Hardened layer have close grains, and arranged in order, its hardness is 1.5 to 2 times of the matrix hardness, about 750 ~ 830HV.

In addition, a number of works have investigated the carbonitride precipitation behavior with micro-additions of titanium, niobium and vanadium steels[10-11].
These micro-alloying elements are also strong carbide formings and act as grain refiners while solution in austenite.
However, the TEM bright-field image of samples with rapid tempering of 40s, as shown in Fig.4(a)(b), presents many islands and a lot of dislocation tangles within grains due to insufficient tempering time.
In this case, the dislocations inside the grains are the nucleation sites of homogeneous fine cementites.
This impact energy is closely related to the size of cementites formation within matrix or grain boundaries.

Hot gases from the igniter are injected into the propellant grains and the whole charge is ignited.
The criterion of ignition, flame spreading and combustion of propellant grains cab be referred to [4].
MP propellant grains; 3.
Since the model assumes propellant grains are incompressible, there is no energy equation for the solid phase.
Rajan, Flame spreading and combustion in packed beds of propellant grains, AIAA 75 (1975) 1-11

The increasing number of papers, based on such kind of methodology, illustrates the interest of many researchers in materials science to the combined analysis [5-10].
Starting 386 from calcined powders composed of Bi2212 and secondary phases such as Ca2PbO4, Ca2CuO3 or CuO, the thermomechanical treatment (temperature and uniaxial pressure) allows simultaneously the nucleation and growth of the Bi2223 phase and the alignment of both Bi2212 and Bi2223 platelike grains.
The initial isotropic microstructure of the sintered material (Fig. 1a), in terms of crystallographic orientations, is modified into a preferential orientation of the grains (Fig. 1b).
The grain alignment is also crucial in order to optimize the anisotropic transport properties of our materials.
The circulation of the current is not only facilitated by a better alignment of grains and a larger percentage of Bi2223 but also by a larger crystallite size which limits consequently the number of grain boundaries, so current barriers in the material.

By decreasing the working pressure, crystallite size increases, simultaneously there is a movement of interstial atoms from its grain boundary to crystallite, consequently lattice defect decreases in the film [12].
It is due to the fact that by increasing the working pressures, the collisions between ablated CIGS atoms moving from target to substrate and Ar gas atoms increases causes less number of randomly moving CIGS atoms reaching to the substrate.
It has been observed that decreasing the working pressure, average grain size of CIGS film increases.
Due to increment in grain size, charge carriers have to cross minimum number of grain boundaries during electrical transport which causes the reduction in sheet resistance of CIGS thin films [14].
It may be due to increment in grain size of film as a result of this potential barrier decrease to a low value for charge carriers during the electrical transport.

It is well known that the solidified microscopic structure with fine equiaxed grain has excellent mechanical property.
Table 2 Orthogonal test Preface number 0 # 1# 2 # 3# 4# 5# 6# 7# 8# 9 # Electric current /A 0 290 380 200 380 200 290 200 290 380 Magnetic field strength /mT 0 93.5 93.5 93.5 291 291 291 331 331 331 Time/min 0 5 15 25 5 15 25 5 15 25 Result and analysis Mechanical property analysis.
The results show that electromagnetic casting can change the structure of liquid metal and can increase the number of nucleus to reach the critical size.
Therefore, the grain is fine and uniform, which improves the mechanical property.
Summary 1�The structure of ZLSi9Mg alloy liquid can be changed by the electromagnetic pump that made the amount of grain reaching the critical crystal nucleus size grow.