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The slit was 0.1 mm and very small grains are imaged.
Bigger grains are seen as longer streaks with the streaklength corresponding to the grain diameter in scanning direction (transverse direction).
They consist of a large number (e.g. >1000) of sharp and narrow peaks (e.g.
For the discussion of the experimental data it is necessary to know more about the relationship between the number of input orientations and the number of agreements with the calculated values.
Figure 18 Relationship between random number N and correlation with the calculated values.

Grain family 2, less in number, has <10 1 0> along the rod axis with the other crystal axes defined by a 360˚ rotation about the <10 1 0> axis.
As a result of cooling, <0002> grains are under tension and <10 1 0> grains are under compression perpendicular to the rod axis.
Along the rod axis grain families 1 and 2 have the same coefficient of expansion and are constrained by grains less in number and with similar coefficients of expansion so the thermal strains in grain families 1 and 2 are nearly zero.
Nevertheless, the thermal strains in other grain orientations along the rod axis, such as grains with <10 1 1> along the rod axis, are tensile although the population of these grains is much lower than grain families 1 or 2.
The Schmidt factors for twinning for grain family 1 and grain family 2 are 0.37 and 0.49 respectively so, to a rough approximation, grain family 2 twins first and grain family 1 only begins to twin when all the appropriate orientations of grain 2 have twinned.

It is important to note that these trends may be noticeably dependent on the number of ECAP passes [5-7].
A coarse-grained Cu-0.2wt.
Dependence of HAGBs on the number of ECAP passes.
This softening may be related to the increase in the spacing of HAGBs at approximately constant subgrain size with increasing number of ECAP passes, resulting in the fraction of low-angle grain boundaries decreasing considerably (Fig. 5).
Both alloys show increased ductility with increasing number of ECAP passes (Fig. 3).

It causes a gap between a sand grain which allows molten metal to pass through the grains of sand that bring off the veining in cast iron appearance.
Grain Size Distribution and Grain Fineness Number [GFN] Sieve analysis was performed to identify the grain size distribution and grain fineness number (GFN).
Grain Size Distribution and Grain Fineness Number (GFN) The results of the sieve analysis are shown in Fig. 2.
The AFS grain fineness number for Australian sand, Rayong sand, Reclaimed sand, and River sand are respectively 54.2, 52.0, 55.1 and 50.4.
Fig. 2 Grain size distribution evaluated by sieve analysis.

The mean grain size and grain distribution and surface roughness were determined by using the Nova NT-MDT Image Analysis Software.
The surface reveals well defined grain boundaries with an average grain size of 15 nm (Fig. 4a).
A mean grain size of the order of 5-10 nm is observed.
Annealing at 400ºC for 2 hours significantly improved the crystalline properties and altered the stoichiometry in the WO3 and Fe-doped WO3 films, which increased the number of oxygen vacancies in the films.
An increase in number of oxygen vacancies is considered to be highly beneficial for gas sensing.

When substituting an actual value of undercooling, one can determine the actual grain density after solidification.
The ratio of the density of nucleation sites (those a microscopic examination of the bulk t which a nucleus has already formed and growth has begun) and the total number of sites per unit volume λ is dependent on the maximum undercooling and is a non-decreasing function.
As a consequence the relative grain density NV(∆T)/λ, i.e. the ratio of grain density to the total density of substrates can be described by a continuous non-decreasing function of the undercooling with the following characteristics: ( )    ∞→∆ =∆ = λ ∆ T T TNV for1 0 for0 . (1) Let ( ) ( )( ) ( )TTNTn V ∆d d λ∆=∆ be the first derivative of the function NV(∆T)/λ with respect to d(∆T), then λ·n·d(∆T) determines the change of grain density in the interval from ∆T to ∆T + d(∆T).
Grain density versus undercooling according to the lognormal and Oldfield models.
Vol. 20A (1989), pp. 311-322 [iii] Fraś E. at al.: Theoretical Model for Heterogeneous Nucleation of Grains During Solidification.

Automated schemes were developed to divide the component into a computationally optimum number of sub-volumes with similar life and risk values to determine total component reliability accurately and efficiently.
The zone sequence is applied in reverse order to identify the minimum number of zones that satisfies component target risk or convergence threshold constraints.
(a) Average Grain Size (microns) (b) Multiplier on Fatigue Crack Growth Rate Figure 2.
Without Grain Size Scaling With Grain Size Scaling (a) Fatigue Crack Growth Life Contours (cycles) (b) Fracture Risk Contours Figure 3.
Ongoing work is developing a similar probabilistic treatment of grain sizes calculated by DEFORM, addressing both the variability in the location-specific average grain sizes as well as variability in the actual grain sizes (with a particular focus on anomalously large grains, which are especially important for fatigue crack initiation).

One of the benefits of the fine grain approach is that one can apply fine grain process to existing alloys such as Ti-64.
(1) Grain Size: Fine grain size is essential for accelerating grain boundary sliding, which is a predominant mechanism of superplasticity.
According to a simple math calculation, reducing grain size by half results in doubling grain boundary area [1]
From the viewpoint of superplasticity, a grain boundary between two alpha grains is a limited contribution to grain boundary sliding.
Mater., vol. 433 (2010), p.49 [4] US Patent Number US 6,786,985 [5] US Patent Number US 8,551,264 [6] H.

Introduction The current interest for the production of fine grained materials by severe plastic deformation (SPD), leads to a large number of investigations focusing on the substructure development and the related mechanical properties.
Both materials were received in as cast condition with an initial grain size of ∼250 µm.
For alloy AA5182Cu these numbers are after 4 ECAP passes 24% HAB and an average (sub)grain size of 2.3µm, and after 8 ECAP passes 42% HAB and 1.4µm (sub)grain size.
� Grain refinement in alloy AA5182+Cu during ECAP, is delayed compared to alloy AA5182
The authors are also grateful for the financial support provided by the Belgian Science Foundation (FWO) under contract number G.0208.02.

The results show that moderate addition of Y and Gd to AZ61 magnesium alloy can obviously refine grains of AZ61 alloy, and decrease the amount of Mg17Al12 phase.
The high-temperature phases precipitate at grain boundaries to the pinning effect on grain boundary and prevent further grain growth, thereby significantly refine the grain.
When the content of Y and Gd is up to 2.7%, the grain is most refined, Y3Al2 and Al2Gd3 phases small precipitation on the grain boundary and in the crystal.
When the content of Y and Gd is more than 2.7%, the number of blocky Y3Al2 and Al2Gd3 phases increased, as well as sizes.
According to Hall-Petch law[6], grain refinement can significantly increase the yield strength of magnesium alloy.