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The grain size, D, was calculated from the crystalline peak shift in Raman spectra using the following equation [8].
Based on the above equation, the grain size of the film was calculated to be about 1.49 nm.
Since large grains are formed due to coalescence, low grain boundary scattering exists in the film, which may leads to an increase in the conductivity and transmittance.
For films deposited on untreated stainless steel, the film is amorphous forming large number of grain boundaries as shown in figure 3.
In this case, both the conductivity and transmittance are low due to the comparatively higher grain boundary scattering.

The authors [5] have developed the low temperature nitriding to suppress the grain-coarsening of CP titanium during the process.
Fig. 4 (a) showed that grain-coarsening did not occur during the nitriding process.
In this figure, the stress amplitude sa, the course of the dissipated energy Edis, the displacement amplitude A and the change in temperature DT versus the number of cycles are plotted.
On the other hand, the S-N curve for the nitrided specimens in the subsurface fracture mode was shifted to higher numbers of cycles compared to the un-nitrided ones.
Fig. 16 Relationship between DKdark and the number of cycles to failure In the next step, let us consider the stress intensity ranges at the edge of surface defects (DKdefect).

The average size of original austenite grains was 11.2 mm measured from 200 grains of intergranular morphology on SEM micrographs taken of fracture surfaces.
For the specimens tested in 3.5% NaCl solution, the ratio of intergranular morphology is 90%, indicating that crack growth along grain boundaries is a dominant mechanism.
From Fig. 6 (a) and (b), it is also seen secondary cracks along grain boundaries, which is the phenomenon of grain boundary embrittlement due to aqueous environmental effect.
Fig. 8 Estimation of hydrogen diffusion depth vs. number of loading cycles.
Such that we may draw the variation tendency of Xd versus t, i.e. the number of loading cycles, as shown in Fig.8, by taking with f being the cycling frequency of 52.5Hz.

The number of visible micropores after sintering has reduced significantly.
The reduction can be related to the grain growth phenomena of the particles upon sintering.
The phenomenon of grain growth upon sintering leads to densification of ceramics and associated with increase in the density values as indicated in Table 1.
However, the amount of visible micropores after densification as shown in Figure 1 (c) and (d) for ceramic composites is still enormous, suggesting the densification at 1150oC is insufficient to reduce the number of large micropores.
However, sintering at 1150oC was insufficient to eliminate the number of pores.

However, compared to the machining process, advantages of parts manufactured by cold heading are almost no waste material, increased tensile strength from cold working, and controlled grain flow [2].
The purpose of this research is to study the feasibility in reducing the number of forging steps used in producing a socket head screw.
Factors to be considered in this work are material grain flow and forging force and tool stresses, which were then used to determine part quality and tool life.
(2) Where is number of lifecycles, is mean stress (MPa), is stress amplitude (MPa), is fatigue strength coefficient (MPa), and b is fatigue strength exponent.
Forging quality from the simulation determined by metal grain flow lines is similar.

Foils with fine grain sizes tend to have less creep resistance relative to coarse-grained products of the same composition.
The addition of Nb further improves in suppressing carbide precipitation at grain boundaries.
These cavities which are initiated at triple-point grain boundaries grew to final fracture of the critical section of the foil specimen.
Elongation of the grains accompanying the grain boundary cavitations process accounts for the observed excellent creep strain of 44 % at fracture of the foil.
Creep failure is signified by the formation of large number of w-type creep cavitations.

Large grains may have sufficient space within the grains for significant numbers of dislocations to accumulate and to intersect/tangle with each other during deformation.
However, in UFG materials the dislocations may no longer accumulate inside grains so that the grain interior is often relatively dislocation-free.
The X-ray peak broadening is due to the combined effect of the structural refinement (finer grain size) and the residual microstrain [22].
Twin boundaries (TBs)/GBs intersections subdivide the original grains efficiently and lead to the formation of the new refined microstructure [24,25].
So it is effective for grain subdivision and refinement by reducing the stacking fault energy.

Grain boundaries on the untreated sample are clearly visible as a result of steel production process.
Authors supposed that improvements of tribological properties are connected with: enrichment of grain boundaries with REE, refining of grain size due to very high cooling rate and nitrogen presence in modified layer.
Number of surface failures was reduced by small REE concentration (0.3 at. %).
Observed grains were smaller with higher REE concentration.
Results of point elemental analysis of single grains of unmodified and modified samples show that observed grains are the oxide particles like in the work of [13, 14] and allowed us to determine the grains structure.

The obtained structure shows equiaxed grains with the average grain size between 70 nm for the sample annealed at 350 C to 0.5mm in the sample annealed at 500C.
Annealing at 500 C produces larger grains of a average size about 0.5 mm.
Annealing at 350oC – 400oC causes formation of nanocrystalline structure, the mean grain size is 70 -100 nm.
Annealing at 500oC leads to well defined large grain structure.
Acknowledgments The studies were financially supported by the Ministry of Education and Sciences, the project number N N507 446834 References [1] R.S.

The average grain size was determined from SEM micrographs using Image-pro Plus software.
The bright-grey and dark-grey contrasts are the ZrO2 and Al2O3 grains, respectively.
During cooling, the t-ZrO2 grains can be transformed to m-ZrO2 if the stabilizer content is below the critical value with respect to grain size.
The presence of small gradient in hardness can be from the different grain size.
G5RD-CT2002-00732, the research fund of K.U.Leuven in the framework of the Flanders-China bilateral projects BIL 04/13 and BIL 04/14, as well as the Shanghai Leading Academic Discipline Project, project number T0101e.