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It was established that the films annealed at T = 600 °C are polycrystalline with the structure of the orthorhombic BaSi2, with grain sizes of 100-200 nm.
Higher anneal temperature (T=750 °C) leads to increase of diffraction peak intensity of BaSi2 phase with grain coagulated into 300-400 nm aggregates.
For sample 13L the grains with sizes of 100-200 nm elongated in the one direction at root mean square roughness σrms = 6.9 nm are observed (Fig. 1a) that confirms film crystallization and grain texture formation.
For the sample 15R the grains of a circular shape with dimensions of 100-150 nm without preferential orientation were formed (Fig. 1b).
In order to calculate such structural parameters as lattice constants (a, b, c), average grain size (d) and grain micro strain (e) the experimental spectra were fitted by MAUD program [8] taking into calculations above mentioned orthorhombic BaSi2 structure.

However, the full benefits of using platinum can only be achieved if a number of simple basic precautions are observed in the daily practice.
The detrimental influence of different “platinum poisons” is summarized by a number of case histories resulting from inadequate caution in practice.
Other examples of “poisons” are phosphorus, boron, bismuth, silicon, sulphur and a number of heavy metals, e.g. lead, zinc, tin, antimony.
The presence of silicon is not surprising, as this will be found at high concentrations in a large number of samples, usually in the form of SiO2.
The carbon has diffused into the grain boundaries leading to grain boundary separation and porosity.

The macrostructure shows that samples with spheroidal and vermicular graphite show much smaller grain size than the flake graphite sample F.
This shows that, for a similar cooling rate, a larger number of austenite nucleus have developed over the same period of time per unit volume, suggesting that a greater nucleation rate of austenite characterizes the solidification of hypereutectic spheroidal and vermicular cast irons.
Two families of grains of different size are observed, as shown in Figure 2.
Some large grains having a size similar to that of gray iron sample F, and other much smaller grains.
A large number of colonies exist within a grain of the macrostructure, assuming that a grain is a portion of the volume having similar austenite crystal orientation.

In the last thirty years, a number of processing techniques have been developed to produce nc-materials.
But the average grain size of the as-prepared specimens is about 100 nm.
The average grain size of the as-prepared nc Ag did not grow much at elevated temperature.
In the annealing of nc-Cu prepared by FLM, the average grain size increased by 50% at 473K.
So the high microhardness in this study derived from ultrafine grain size (18.5 nm).

· High-angle boundary grains do not significantly grow after tempering; on the contrary, low-angle grain boundaries (cells) move, fully justifying the hardness evolution with tempering temperature.
The austenite grain size was measured according to ASTM E112.
Packet size versus austenite grain size.
This result allows to suppose that a straininduced mechanism of martensite formation is actually operating and that the reduction of the packet size in the central region is the consequence of the activation of a higher number of martensite nuclei per unit volume compared with the subsurface zones.
On the contrary, grains with low-angle grain boundaries (cells) move.

Controlling growth of ferrite grain is the key to improve toughness of the heat affected zone (HAZ).
It was found that the best size of Ti(C/N) grain is 2-5µm and content of martensite is 40%.
If it is high cooling rate, then grain size will be fine rather than coarse.
The size of ferrite grains in HAZ correlates with welding heat input.
The best favourable size of Ti(C,N) grain dispersing around ferrite grain is 2-5µm [2].

The higher Fc value, the more round of the α-Al grain is.
As seen from Fig. 2(a), the α-A1 primary grains in the sample were not of uniform size and the fine grained regions were detected.
As seen from Fig. 2(b), the distribution of α-A1 primary grains in the sample were uniform and the average grain size was 38µm with the casting temperature up to 740℃.
Temperature(℃) Temperature(℃) Fig. 3 The relationships of the average grain size and the average equivalent roundness of the squeeze-cast Al-Zn-Mg-Cu alloy with the casting temperature According to the thermodynamics law, the nucleation in molten metal is more and more difficult and the crystal nucleus number which can be kept is less and less with the increasing physics heat supplied by melt temperature.
The grain size constantly decreased with the increasing Al-10RE refiner.

Quaternion is a number that extends the complex number, and can represent the three-dimensional orientation and rotation.
A quaternion is a number that extends the complex number and expressed as , where and are imaginary units satisfying the following relationships: (2) A quaternion can be considered as a number containing one scalar element and one three-dimensional vector element, so that a quaternion can express a three-dimensional rotation.
The both crystal grains grow isotropically.
When the crystal grains come in contact with each other, the grain boundary is formed due to the misorientation between two grains.
In contrast with the case 1, the grain boundary is not formed when the crystal grains come in contact with each other, and two grains merge into a single grain, because two crystal grains have the identical orientation.

The degree of splitting of {111} grains is higher than {100} grains [18,28].
As the number of rolling process increases, the recrystallization temperature and grain size decrease.
If the annealing temperature rise, grains will be coarse which is not conducive to obtaining fine grains.
On the other hand, the growth of {111} grains will consume {100} grains.
Long, Pass number dependence of through-thickness microstructure homogeneity in tantalum sheets under the change of strain path, Mater Charact. 160 (2019)

These results are described in the present investigation together with a summary of unpublished data on the thermal properties of a number of UHCSs.
The grain size in the coarse grained UHCS was reduced to 7 μm by a subsequent cold rolling and recrystallization process.
The average linear grain size is less than 5 μm.
Thermal expansion tests were pursued at the Lawrence Livermore National Laboratory on a number of UHCS-1.6Al materials containing different amounts of carbon.
A limited number of tests were done on the mechanical properties of UHCS-10Al materials at room temperature.