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When the bias voltage is -60V, the coatings, composed of fine grain aluminum and massive tin, has a loose structure.
With increasing sputtering time, the island groups of atoms are combined with new grown by sputtering over the atom, and the number will gradually saturated island, isolated islands interconnected into a layered form[6].
It enhances grain refinement and density of the coating.
With the increase of the sputtering time, the island groups will be combined with new sputter atoms and gradually grew up, and the island also gradually saturated, the number of isolated islands are connected into a layered form.
Summary （1）The microstructure of the unbalanced magnetron sputtering AlSn20 coatings changed from coarse grains to fine grains is observed when the bias voltage is raised from -60V to -100V

In the case of filler metals, a titanium addition increases the number of crystal nuclei and causes considerable refining of the weld metal grain.
Microstructure of soldered joints using pure zinc (a) and eutectic alloy ZnAl4 (b) as a filler metals While analysing the results of the microscopic tests one can notice a slight difference in the grain size of the applied filler metals ZnAl4 and Zn+Ti (Fig. 6a, 7b).
In turn, the use of pure zinc as the brazing filler metal enabled obtaining joints with a coarse-grained structure (Fig. 7a).
Therefore it is justified to state that even a very small addition of titanium (approximately 0.07 %) is the most likely reason for an increase in the number of crystal nuclei during the crystallisation of the braze and, as a result, significant grain refining.
According to reference publications [5], this phase is most probably the phase Zn16Ti, which, apart from grain refining, is also responsible for increasing the shear strength of the brazed joints.

The aim of the thermal treatment was to achieve a totally crystallized fine-grained structure.
A: ratio r = at. % Mo / at. % Fe r = 0.02 (mean grain size d ~ 150 nm), B: r = 0.09 d ~ 150 nm) and C: r = 0.83 (d ~ 30 nm).
According to authors of ref. [7], A-B regime can be expected when the mean diffusion distance tD=α (D - coefficient of volume diffusion, t - diffusion time) in the bulk adjoining the grain boundary (GB) is comparable with the grain size d : α α 43.0 ≤≤ d
Acknowledgements This work was supported by the Grant Agency of the Czech Republic, project number 106/04/0228 and by IPM AS CR, project number AV0Z20410507.
Gust: Fundamentals of Grain and Interphase Boundary Diffusion (Ziegler Press, Stuttgart 1988)

Introduction The discovery of giant and colossal magnetoresistance in doped lanthanum manganite, La1-xAxMnO3 (A = Ca, Sr, Ba…), thin films [1] and polycrystalline samples [2], respectively, has attracted interest for a number of research studies related to those perovskites.
These systems are known to exhibit a number of unusual and interesting electronic and magnetic properties, among which the insulator-metal transition and the CMR effect are probably the most dramatic one.
The effect of grain boundaries in the polycrystalline manganites has been studied intensively, where the grain’s shape and microstructure will be changed with different preparation process or dopants.
This might be due to the existence of the antiferromagnetic or disordered insulating region at the grain boundary [12].
In polycrystalline samples, these disordered phases at the grain boundary influenced the electron transport and weakened the double exchange DE mechanism.

After sintering, an electrolyte YSZ film was deposited on a number of the samples by means of reactive magnetron sputtering.
The growth of crystalline nickel grains occurs due to small-sized grains and is associated with the minimization of the surface free energy.
This process is generally dependent on a grain size and temperature.
It is assumed that the metal grain growth typically occurs under two conditions.
Li, Grain growth in electrodeposited nanocrystalline fcc Ni-Fe alloys, Scripta Materialia, 55 (2006) 263-266

Nanopowders of WC with grain sizes less than 100 nm became the subject of active research in recent years [2,3], due to the significant roles of grain-size reduction played in the enhancement of mechanical properties of WC-Co hard alloys.
A number of studies [4-6] of the WC particle morphology showed that WC grains have the shape of a truncated triangular prism due to the crystal structure of hexagonal tungsten carbide.
It had been shown that the grain size reduction from about 4.8 µm for the polycrystalline cobalt to 12 nm for the nanocrystalline cobalt increased the tensile strength from 0.81 GPa to 1.86 GPa [9].
Wahnström, Morphology of WC grains in WC-Co alloys, Materials Science and Engineering A 486 (2008) 253-261
Allibert, Morphology of WC grains in WC–Co alloys: Theoretical determination of grain shape, Acta Mater. 55 (2007) 1515-1521

EBSD measurements on the fatigued samples after fracture were conducted to measure the local texture at selected points and to investigate the crack initiation with respect to the grain orientation.
A significant inhomogeneity is observed in this microstructure, which contains both large grains and small equiaxed grains.
The average grain size is about 8 μm.
Moreover, a minor texture component is observed in the centre of the pole figure, which corresponds to grains having their c-axes aligned along the transverse direction (TD).
S-N curves in the different loading directions, 0, 45 and 90° to the extrusion direction; the arrows indicate run-out conditions and the asterisks numbers of run-out samples.

A number of studies have investigated sintering fly ash using conventional ceramic firing cycles, involving relatively slow heating and a controlled dwell at maximum temperature.
It can be noticed that angular shaped grains are present while the spherical shaped particles are no longer seen in all samples.
Equiaxial polygonal grains (monocrystal) of size3-5μm are observed in the obtained samples with 40wt% addition of K2CO3·1/2H2O.
Compared to micrograph of the K40 samples, grains formed in K20 samples are connected into a bunch and have smaller sizes.
SEM images confirm equiaxial polygonal grains (mono crystals) of size3-5μm are formed in the obtained samples with 40wt% addition of K2CO3·1/2H2O.The presence of many elongated grains due to well-developed potassium aluminum silicate crystals is conductive to the better sintering properties.

There have been a large number of reports in the literature on the microwave interaction with materials including the type of processing microwave heating can offer [3, 4].
The smaller grain sizes and particle formation allow for more densification.
The microwave plasma sintered samples show greater strength indicating the uniformity of the structure and the smaller grain formation.
This heating can have an effect on the grain formation and structure of the sample.
The higher pressures allow necking of the particles within the composition due to the larger grain formation.

The sintering temperature of this material, however, is as high as 1773 K and the grain growth is extremely inhomogeneous [4].
The added B2O3 also produced an increase in grain size (Table 1), indicating the existence of liquid phase sintering in those B2O3 added samples.
Fig.4 Variation of Vickers hardness number with B2O3 content.
It is possible that partial amount of B2O3 might deposit to grain or grain boundaries and resist to the crack that pass through the grain and grain boundary as a result of the increase in the hardness value due to its high mechanical properties [10].
Amount of B2O3 Grain size (µm) Lattice parameter (Å) c/a d33 (pC/N) AC resistance at 100 Hz (105 Ω•cm) a c undoped 19.8 4.0159 4.0247 1.0021 104 4.3 1 wt% 25.7 4.0181 4.0281 1.0025 107 2.0 2 wt% 28.8 4.0182 4.0286 1.0026 - 1.2 3 wt% 30.6 4.0262 4.0299 1.0009 - 2.6 SUMMARY The properties of B2O3 doped Ba(Sn0.1Ti0.9)O3 ceramics were investigated.