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The initial material has a recrystallized microstructure with grain sizes of 6−9 µm.
Grain size measurements of the initial materials were performed with the linear intercept method on 500−700 grains in optical micrographs in the area between sheet middle and sheet surface (transition area).
In addition, grain boundary sliding can also occur at room temperature, which leads to higher ductility [6–8].
Acknowledgements The authors wish to acknowledge the financial support of the SMiLE project (“Systemintegrativer Multi-Material-Leichtbau für die Elektromobilität”, project number: 03X3041O) by the German Federal Ministry of Education and Research.
Koike, New deformation mechanisms in fine-grain Mg alloys, Mater.

For example, it has been shown that classical methods for increasing the strength and yield stress of polycrystalline materials are applicable when the size of grains in a polycrystal is reduced only to a grain size of several tens of nanometers.
Table 1 shows the measured compositions of inclusions corresponding to the numbered points in Fig. 1.
Besides that, the samples with the addition of zinc oxide contain thin layers of the second phase on the borders of the grains or grain agglomerates.
Baretzky, Increase of Co solubility with decreasing grain size in ZnO, Acta Mater. 56 (2008) 6246–6256
Straumal, Increase of Mn solubility with decreasing grain size in ZnO, J.

This is in contrast to the particles in Ti 6Al 4V 0.9La located mainly on the grain boundaries.
Black spots refer to metallic La particles which are situated on the grain boundaries (left) or on grain boundaries and inside the grains (right).
When the cast bars were deformed by rotary swaging the defects became larger leading to a high number of intercrystalline cracks.
Ti 6Al 2Fe 1Mo 0.9La 0.5Cu alloy and modifications containing Fe showed particles on the grain boundaries as well as in the grains.
Acknowledgements Financial support of the Arbeitsgemeinschaft industrieller Forschungsvereinigungen, AiF (project number 16112 N), is gratefully acknowlegded.

The grain structure in the HAZ is shown in Fig. 1(d), where the grains became coarser.
In the fine equiaxed grain structure in the WNZ (Fig. 1(b)), which decreased both the distance of dislocation glide and the number of dislocation pile-ups before obstacles, it was difficult for the microcrack to form via micro-stress concentration.
The microstructure of the AA2219-T62 alloy consisted of elongated and pancake-shaped grains with network-like second-phase particles along grain boundaries.
After FSW, the grains in the WNZ became recrystallized fine and equiaxed grains with fine dispersed second-phase particles.
The TMAZ exhibited elongated recrystallized grains along the direction of maximum shear stress and HAZ contained coarser recrystallized grains.

Size profiles can be modelled by assuming log-normal size-distribution of grains or subgrains [5,6].
The twin boundary frequency, β, was measured in a number fcc metals deformed ECAP [18] and in two Cu-Zn alloys deformed by high pressure torsion (HPT) [15,16].
Coarse grain commercial purity (CP) Ti was hot rolled at 720 oC and cooled to RT in air [19].
X-ray diffraction patterns of ultra fine grain CP-Ti produced by ECAP [30] were revisited for twinning.
In ultra fine grain CPTi or AZ91 Mg alloy no twinning is observed by the ECMWP method, in spite that in the coarse grain conterparts twinning is concomitant to dislocation slip.

In the present tests, rolling speed was 3000 rpm, maximum Herzian contact stress was 5.6 GPa and target number of cycles was 2.0×107.
In order to measure the prior austenite grain size (PAGS), we used the intercept method [8].
At depth ranging from 0.32 mm to 0.85 mm, some big prior austenite grains can be seen.
More than 70% of the cracks were observed between the surface and 0.3 mm depth, and the number of cracks decreased as the depth increases.
[8] ISO 643, Steels - Micrographic determination of the apparent grain size, 2003

In general, these ceramics are obtained by solid-state reaction, which favors the formation of micrometric grains.
The ceramics obtained from both sintering methods showed substantial differences in microstructure such as presence of piroclore phase and grain morphology.
The PZT molar ratio of 53/47 (Zr/Ti) exhibits high dielectric constant, piezoelectric and electromechanical properties [2] due the large number of possible directions of the spontaneous polarization present in its structure.
In both cases there was the formation of secondary phase, characterized by the presence of grains in the pyramidal shape.
The measured values for the grain sizes were (3.1 ± 0.1) µm and (3.9 ± 0.3) µm respectively.

Meanwhile, lattice constant, crystal grain size and residual stress situation of films as-deposited were calculated and discussed in detail.
With the increasing of the oxygen flow rate, grain size and surface roughness of films as-deposited decreased, and inner stress remained in film increased.
The contrasts of bright granules and dark ones in image (a), deriving from the height difference of grains in the direction perpendicular to the film surface, indicated a rough surface morphology with a large number of structural defects.
The surface of film deposited at oxygen flow rate 40sccm was stacked of triangle flake-like grains, the well defined grain structure indicated a smoother and denser surface morphology than film deposited at oxygen flow rate 30sccm.
The SEM images showed that at low oxygen flow rate, the surface of ITO film was piled of round-shape grains, and the surface of film deposited at relatively high oxygen flow rate was stacked of triangle flake-like grains.

Introduction Refining the grain size plays a central role in improving the mechanical properties of superalloys, One of the main ways to control grain size is via thermomechanical processing (TMP).
It depends on the rheology of the material (strain hardening and dynamic recovery) and involves the nucleation of new grains and the migration of grain boundaries as well.
Materials and Procedures Commercial superalloys have a complicated metallurgy and contain a large number of alloying elements.
Such an intermediate temperature was chosen to restrict grain growth.
Derby relationship between flow stress and average steady-state grain-size.

The grain size of weld metals with resistance value 30Ω is finer than 15Ω and 45Ω.
The grain size of weld metals with resistance value 30Ω is finer than 15Ω and 45Ω.
The substantial grain growth has occurred with proper values of heat input [10].
The tensile strength of weld metals is correlated with the grain size of microstructure.
· There were no significant trend difference the hardness number of base metal, HAZ and weld metal of aluminium alloy 5051 because it is non-heat-treatable material.