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In turn, the Elektron 21 alloy before the modification contained grains of both dendritic and cellular morphology and only grains of cellular morphology after the modification.
The measurements of size and shape of the grain in tab. 5 and 6.
WE43 - mod. acc. to MEL WE43 - mod. +50% WE43 - mod. +100% grain size area of flat section A [µm2] 1706 534 442 293 number of grain per unit area NA [mm-2] 570 1841 2222 3336 relative area of grain boundary SV [µm2/µm3] 0.066 0.104 0.110 0.131 heterogeneity of the grain size variation coefficient A ν(A) [%] 72 111 121 143 grain shape shape factor ξ - 0.553 0.647 0.666 0.680 elongation factor δ - 1.62 1.70 1.68 1.66 Table 6.
E21 - mod. acc. to MEL E21 - mod. +50% E21 - mod. +100% grain size area of flat section A [µm2] 2987 459 421 452 number of grain per unit area NA [mm-2] 328 2138 2328 2171 relative area of grain boundary SV [µm2/µm3] 0.045 0.118 0.120 0.113 heterogeneity of the grain size variation coefficient A ν(A) [%] 99 92 101 101 shape factor elongation factor ξ - 0.642 0. 622 0. 617 0. 624 area of flat section δ - 1.65 1.67 1.71 1.66 The fractographic investigations revealed the existence of non-metallic inclusions on the surfaces of fractures.
The size of the grain decreases along with the increase of the amount of modifiers, apart from the +100 modification variant, with which the size of the grain insignificantly increases.

Introduction Environmentally-induced intergranular stress corrosion cracking (IGSCC) is known to be a damaging mode in number of nickel-base alloys used in pressurized water reactors (PWR) of nuclear power plants [1-5].
Indeed, the migration of chromium atoms towards the surface throughout the lattice generates a contraction of alloy grains, hence stressed grain boundaries.
The microstructure of the model alloys was characterized by equiaxed small grains (ASTM grain size number = 8 - 9) and very few carbides (Fig. 1).
The layer appears not to have been a compact continuous one but instead was formed of discrete separated grains.
Another layer of very small oxide grains can also be distinguished underneath the crystallites.

It is not possible to create the trajectory of an abrasive grain or a resultant trajectory of a set of grains unless the grinding conditions are considered.
,n) exhibits a certain degree of stochasticity, where n is the actual number of abrasive grains in l.
Let m be the expected number of abrasive grains in l.
(1) Equation (1) simply means that one can continue to do i = i +1, if Lgi £ l is true; the final value of i is the number of grains n.
This yields drgi = d - dgi (error in the depth of cut), rgi = rG - drgi (grain radius), Dgi = 2rgi (grain diameter), Vgi = wGrgi (grain velocity).

The latter considers different kinds of recrystallization as the same process rooted in nucleation and grain growth.
The number of nuclei per volume unit NV corresponds to the number grain per volume after full recrystallization, whereas number of nuclei per volume unit NV can be easily calculated from the final grain size after metadynamic NVmd = f(Dmd) or static NVsrx = f(Dsrx) recrystallization.
An equation for nucleation rate can be presented in the form: , (5) where: - the nucleation rate during static recrystallization [mm-3s-1], NVmd - number of grains per volume unit after metadynamic recrystallization.
Growth of recrystallized grain can be calculated according to following differential equation: , (6) where: DS – grain size [mm], - grain growth rate [mm/s], Ddrx - dynamically recrystallized grain size [mm].
Identification of model parameters For the model parameters identification, a nonlinear least-squares (nonlinear data-fitting) problem with constrains must be solved: , (9) where: n – a curve number, i – a point number, pn – a weight of the curve with the number n, kn – a number of the points on the curve with the number n, l – a number of the curves, σmni, σcni –flow stresses for the point number i on the curve number n, measured and calculated respectively, σnmax – a maximal value of the flow stress for the curve number n.

Lower calcining temperature and inadequacy of holding time led to an incomplete combustion of organic matter, which result in, a large number of pore entraining into BSPT ceramic when sintering.
Grain growth was apparent during the first heating step, as temperature rising, the rate of grain boundary Fig. 3.
Analysis of grain size effect.
The trend of grain size effect was shown in figure 8.
The trend of grain size effect of BSPT bulks.

The grain sizes of material were also measured with the comparison method.
Table 2 Material grain sizes Temp[℃] 800 900 1000 1100 Grain sizes grade 9.5 8.5 8.0 7.5 Fracture Roughness Measure Method of Roughness.
The roughness parameters Rc and Ra are related with the grain size of the material for 16MnR steel.
Acknowledgement The research work is supported by Nature Science Foundation of Anhui Province Education Department (Grant Number:KJ2009A126).
The research work is supported by Nature Science Foundation of Anhui Province Education Department (Grant Number:KJ2008A144).

These nodules are composed of finer grains less than 5nm as shown in Fig. 2c.
This can be explained in terms of its finer grain size with higher active.
The only different is the number of nanoparticles and their sizes.
In this study, P25 coating presents "cauliflower" structure with about 5nm in grain size which increases significantly the number of active sites and contact areas with benzene.
The only different is the number of nanoparticles and their sizes.

Introduction Nanocrystalline alloys are composed of grains in nanometer scale (typically < 100 nm) and a large number of grain boundaries.
The grain boundary diffusivities of Cu in a severe-plastic-deformation-generated nanocrystalline nickel with a grain size of ~ 300 nm are ~4-5 orders of magnitude higher than those in the coarse-grained nickel [2].
For comparison, the nitriding was also conducted in the same processing condition on a coarse-grained Ni-10 Cr alloy (mean grain size: ~ 36 µm).
Clearly, the Ni-CeO2 nanocomposite was nano-grained with an average grain size of ~50 nm (Fig. 1a), while the electrolytic Ni was submicro-grained with a mean grain size of ~0.5 µm (Fig. 1b).
Such a high number density of nanoparticles dispersed in the nanocomposite would significantly increase the numbers for CrN nucleation.

However, annealing process at 500oC displayed a smaller number of this phase and lower in hardness scale [4].
The grain boundaries number which was intercepted by measuring line were counted and ASTM grain size number would be achieved by the following equation PL = PLTM (1) G=[-6.6457 log⁡(1PL) ]-3.298 (2) Other specimen will also be tested in X-Ray Diffraction machine to obtain the phases which were present after annealing process.
The number of twinning in a microstructure is also inversely proportional to the grain size.
A high ASTM grain size number indicates a finer grain size (smaller grain size) which mean annealing process will enlarge the grain size but minimize the grain size number that can be seen in the Figure 1.b [8, 9, & 12].
The hardness number of the specimens are dropped significantly from 400oC annealing temperature to 500oC which indicate the recrystalization process was occurred and new grains were formed during this stage.

CORe is a pure growth model and therefore, separate nucleation models are required to provide number and orientations of nuclei [3].
The average number of nuclei amounts to ~10 nuclei per deformed Cube band length of 50 µm in rolling direction (Fig.7).
According to this model the number of nuclei is determined by the thickness of the Cube band and can be given by the so-called nucleation parameter �c - the number of recrystallised Cube grains per deformed Cube band.
If several separated bands are introduced instead one big deformed Cube grain, the number of possible nucleation sites on the Cube-S boundaries is increased, which can influence the volume fraction of RX Cube grains.
About 70% of all Cube grain boundaries were boundaries to S grains.