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Introduction Over the past decades, spray forming has been demonstrated for a cast-powder method of the production of homogenously solidified fine-grained and can eliminate macro-segregation materials with exceptional properties, due to rapid solidification[1-2].
For the as-cast H13 steels, coarser grain and carbides, and tempered martensite can be observed in Fig. 2(a).
A number of needle-shape precipitates with 80-100 nm in length and 10-20 nm in thickness are observed.
After tempering, carbides are distributed in grain boundary and martensite interior, which pins dislocation movement and improves the performance of the materials.
With the increase of isothermal temperature, the grain size increases gradually.

Among the factors that determine the effectiveness of the protective action of zinc coatings, the size of zinc grains, the structure and porosity of the coating, which are determined by the method of obtaining the coating, are studied.
As a result of rolling, the large-crystalline columnar structure of cast zinc turns into a deformed fine-grained one [11], which leads to a change in the corrosion behavior.
The reason for the high intensity of corrosion of cast zinc and electroplating is their loose structure: coarse-grained columnar cast zinc and high-porosity electroplating.
The fine-grained deformed structure of rolled products and the intermetallic layers of the hot-zinc coating combined with each other explain their high corrosion resistance in the studied corrosive environments.
The pitting sizes are 1÷10 microns (Fig. 1), and their number increases with in-creasing corrosion time.

Research Methods For the approximation of experimental data in various works, a large number of dependences were proposed, obtained on the basis of their generalization.
In them, an attempt was made to take into account the influence of the constant component of the load on the endurance limit of steel [13, 9, 14, 15, 16], etc. do not clearly reflect the law of variation of the limiting amplitudes at σm≫σт, and do not take into account the effect of the grain diameter of the structure.
The effective threshold stress intensity factor at the crack tip, according to the conclusions for the plane stress state [15], can be calculated from the dependence: Kth0e=Kth0 1-σielσmσ0,2RMCe∙Dσ0,2m+12m, (5) where RMCe is the resistance to micro-cleavage for a plastically deformed structure of the material with grained micro-cleavage calculated through the effective grain of the material RMCe=1,618…1,7∙5,7dz, MPa; D is the overstress factor that takes into account the increase in the first main stress in the case of a complex stress state.
The grain diameter of the metal dz for ferrite-pearlite steels with σт<400 MPa in the absence of experimental data can be calculated using the empirical formula for ferrite-pearlite steels given in [12, 22].

The method of laser welding has a number of advantages in comparison with other welding technologies.
The crystallographic planes of some individual grains of BM were served as a "substrate" for the dendritic solidification of the weld metal (Fig. 5, b).
The cracks were located in both the weld metal and the BM, and propagated along the grain boundaries.
It should be noted that the grain size of the austenite of the BM and the HAZ is the same, both in Cr-Mn-N and in Cr-Mn-Mo-N-steel.
The micrographs of these two investigated steels had shown that the weld metal dendrites were in the conjugation with the crystallographic planes of the BM grains.

Assuming that only Cr2O3 is formed for Ni30Cr and using the mass gain per volume of bulk oxide, an oxidation constant kc value given by 2 [] c ox o ox p k M bM k  (2) has been calculated, where Mox and MO are, respectively, the molar mass of the oxide and of the oxygen atom; b is the number of the oxygen atoms and ρoxide, the oxide density (ρox = 5.21 g.cm-3 for Cr2O3).
The uppermost scale of Ni20Cr specimens exhibits the typical platelet-like morphology [Fig. 4 (a)] ascribed to the NiO, which probably grows before the underlying Cr2O3 tiny grains according to the Raman results.
In both cases, it appears that after a few hours of exposure until 8h, the oxide scale consisted mainly of Cr2O3 [Fig. 4 (b) and (d)] and the grain coarsening may trigger sub-parabolic or decreased kinetics.
Considering the Cr content as well as the oxidation temperature, inward diffusion of oxygen seems to be promoted, preferentially at the grain boundaries [Fig. 5 (a)], which leads to internal oxidation over a few microns.
Taking into account the TGA results [Fig. 1], this phenomenon is very likely to occur during the first parabolic step (with a lower kp) and has been attributed to a higher anionic inward diffusion, especially at the grain boundaries [Fig. 5 (a)].

The aim of the present work is to clarify the influence of a larger number of chemical and structural features on the reaction kinetics.
All the Si-C-O fibres consist predominantly of nanometric b-SiC grains, but contain also free aromatic carbon as basic structural units (BSUs) and amorphous silicon oxycarbide (evidenced by XPS) [8-10].
Figure 1 : Si-C-O ternary diagram showing the composition of the specimens b-SiC (wt.%) Cfree (wt.%) SiOxCy (wt.%) b-SiC grain size (nm) Tyr S 35.1 17.4 47.5 1.2 Tyr Lox-M 71.7 15.4 12.9 1.9 Tyr ZMI 74.8 15.9 9.3 2.2 Tyr AM 51.5 18.0 30.5 2.2 NL101 42.3 12.2 45.5 1.7 NL207 62.9 10.3 26.8 1.9 Hi-Nicalon 88.7 10.4 0.9 5 Hi-Nic S 98.1 1.5 0.4 50 Table 2: Phase composition of the fibres (as deduced by XRD and Table 1).
This is also supported by the low activation energy obtained for the oxygen-rich specimens and the common high Ea value for the O-free materials; the slightly different K values are rather related to the grain size and/or the occurrence of free carbon in this case (Hi Nic. & Hi Nic.
The continuity of free carbon (its percolation state, assessable from the electrical conductivity level s), the average SiC grain size and the presence of heteroelements, even at low level, should also be examined.

Fine-grained granite is the third most common rock type (11%) and pegmatite is the least occurring type (2%).
The same four major rock types, Äspö diorite, greenstone, fine-grained granite, and pegmatite, have been distinguished in DD0092G01.
Greenstone is medium-grained and constitutes 38% of the hole and mainly occurs at upper half of the hole.
Fine-grained granite constitutes 25% of the hole-surfaces.
The plane thermal-mechanical coupling geometry is a quarter circle generated by FLAC FISH grid generation tool with an inner radius of 0.875m and an outer boundary of 20m, and the total element number is about 2000.

However, a number of difficulties have been identified, mainly in the case of fusion welding techniques.
Microstructure of FSW joint: a-SZ; b-TMAZ; c-HAZ; d-BM; e-transition zone [10] recrystallized grains of alpha phase Fig. 3a.
In the heat affected zone the plastic deformation is absent or insufficient to change the original grain structure.
The grain size changes from base MMC to stir zone can be seen clearly in Fig. 3e.
This joint efficiency is due to very fine recrystallized grains structure in the stirred zone.

CS spraying parameters Value CS standard conditions CS innovate conditions Substrate Surface Preparation Ground [(20 grit) Ground (120 grit) Gas utilized Nitrogen Nitrogen Gas Temperature 800 [ºC] 1100 [ºC] Gas Pressure 40 [bar] 50 [bar] Spraying distance 50 [mm] 50 [mm] Transverse speed 500 [mm/s] 500 [mm/s] Number of Passes 4 4 Track spacing 1 [mm] 1 [mm] Spraying angle 90º 90º Nozzle Type Conventional Type SiC, water-cooled Feedstock Powder Ti6Al4V Ti6Al4V Powder feeder wheel rotational speed 3 [rpm] 3 [rpm] 3.3 Mechanical characterization Depth sensing indentation tests were carried out on the coatings for measuring the hardness (H) and elastic modulus (E).
The microstructure of the analysed CS Ti coatings was constituted by splats formed by small grains, ranged from a few microns to submicrometric size.
It presents an equiaxial grain microstructure, with a very well defined grain boundary, and a lower grain size compared to the splat size of the high temperature deposited CS coating.

The ceramic block industry in Brazil employs a considerable number of people and consumes a lot of natural raw material, the clay soil, which must have physical, chemical and mineralogical characteristics compatible with its intended application.
Part of the sample was collected to check the hygroscopic moisture and actual grain density.
The determination of the actual specific mass of the grains of the raw material was carried out according to the prescription of ABNT NBR 6508: 1984 [19] and ABNT NBR 6457: 1986 [20].
The actual grain density found was 2.32 g/cm³ (Solo A), 2.92 g/cm³ (Solo B), 2.74 g/cm³ (Solo C) and 2.68 g/cm³ (Solo D).
Kuzmin, Fine-Grained Concrete of Composite Binder, in: IOP Conf.