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The grain size of CVD-SiC(C) is bigger than that of CVD-SiC(N).
Methyltrichlorosilane (CH3SiCl3 or MTS) has been employed frequently to deposit SiC because of the same number of silicon and carbon atoms in one MTS molecular and thus it is easy to prepare stoichiometric SiC [15-19].
Fig.5 Grain size of CVD-SiC(C) and CVD-SiC(N) calculated according to Scherrer formula.
As can be seen, the grain size is 54nm in CVD-SiC(C) and 46nm in CVD-SiC(N).
The grain size of the CVD-SiC(C) is always 6-7nm bigger than that of CVD-SiC(N).

The value of Si is from 1 to Q and Q is the maximum value of the grain orientation.
Grain boundary is formed among the adjacent sites with different orientation.
If the new orientation is accepted, the site may belong to other grain, otherwise the site belongs to the old grain.
One MCS is equal to the attempt step times N which is actually the total number of crystal lattice sites in the simulation domain.
Gao et al.[9] related the Monte Carlo simulation time (tMCS) to real time by two different models, which are a grain boundary migration model and an experimental data based model, and the two models is given by Eq. (1) and Eq. (2), respectively. 1 2 2 2 0 2 2 2 1 1 4 ( ) exp exp n m a a MCS a L AZV S Q t t K � hK R RT γ λ λ     ∆  = + −             (1) 1 0 1 1 ( ) exp ( ) n n n a MCS n L Q K t t K K RT λ λ ⋅     = + −         (2) where tMCS is Monte Carlo simulation time, t is real time, L0 is the initial grain size at t=0, K1, n and n1 are model constants, λ is the lattice point spacing, γ is grain boundary energy, A is the accommodation probability, Z is the average number of atoms per unit area at the grain boundary, Vm is volume of specific mol, Na is Avogadro's number, h is Planck's constant, K is Boltzmann's constant, R is the gas

Average grain size statistics.
The cracking at the grain boundaries of the grain 1 and 2, and expanding along the grain boundary is shown in Figure 8a.
The crack of the grain 1 continues to expand into grain 3, 4, 5, 7 and 8, as shown in Figure 8b.
Therefore, different grain sizes will lead to the number of grain size changes which satisfy the critical event of cleavage fracture under the same conditions.
It implies that the size and number of the coarsest grains in the grains should be controlled, improving the fracture toughness of the A508-3 steel. 5 Conclusion 1) The brittle fracture mode of ductile-brittle mixed fracture is cleavage fracture.

Then the model was used to study the creep damage development in the welded joints where four different material properties, base material, coarse-grained HAZ, fine-grained HAZ, and weld material, are taken into account.
Fracture predominantly occurs by nucleation, growth and coalescence of voids on grain boundaries.
During the past years, a number of creep damage models were proposed in order to describe the nonlinear creep behaviour of solids at high temperatures.
The creep behaviour of each of the material regions of a weldment is described with a set of physically based constitutive equations, which incorporate a number of state variables.
Becker et al. [4] presented a number of benchmark examples covering uniaxial, biaxial, triaxial and multi-material stress situations to verify the numerical solutions for creep damage.

The processing route significantly affects the grain refinement and grain shape.
The number of ECAE passes was limited to 3.
However, a gradual decrease in the recrystallisation temperature could be noticed with increase in the number of ECAE passes.
[8] on route Bc deformed 5052 Al-alloy reveals that softening starts at a lower temperature for the material subjected to higher number of ECAE passes.
They also proposed that the heat release at a lower temperature is due to recovery in non-equilibrium grain boundaries.

There are a number of observations [1-8] demonstrating that β-phase contributes to the SCC of AlMg alloys.
Samples were solution heat-treated (SHT) at 450°C for 30 minutes, followed by air-cooling, and then given one of a number of sensitisation heat treatments (see Table 1).
Grain boundary attack was found to vary greatly among individual grain boundaries.
The boundary between grains 1 and 2 shows continuous attack, the boundary between grains 1 and 3 as well as the boundary between grains 2 and 4 show discontinuous attack, whereas the boundary between grains 2 and 3 shows no attack.
This different susceptibility to corrosion attack for each boundary can be related to the grain boundary crystallographic misorientation using EBSD. 0 10203040506070 Attacked mode Misorientation angle, degree continuous discontinous unattacked Assessment of a large number of boundaries has shown that there is a threshold in the vicinity of 20°, below which there is negligible attack (Fig. 3).

HECAP opens new possibilities for improving equivalent strain in same number of passes as compared to ECAP.
The production of materials with ultra fine grain sizes which can be achieved by subjecting coarse grained metal to Severe Plastic Deformation (SPD) to improve their mechanical and physical properties [5-9].
The magnitude of channel and corner angles along with the number of passes determines the shear strain induced into the sample.
It can also be predicted that number of passes plays a significant role in strain evolution and average equivalent strain increases with increase in number of passes both in HECAP and ECAP.
· Channel angle and number of passes plays a significant role in evolution of strain

In substituting the real experiment data, a verification experiment for the machining volume and grain wear forecast of concrete diamond grinding tool was conducted using grinding parameters as input value and machining volume and grain wear as output value.
The example result indicated that the model can precise forecast them machining volume and grain wear of diamond grinding tool.
The general form of a grey model is, in whichis progression of grey differential equation andis the number of the variable [3].
Experimental condition and method To gain information about the fundamental correlations between process parameters and work piece specifications, experimental data about the single diamond grain scratch tests in grinding concrete.
Table 2 Comparison between real value with simulation value on cutting speed factors test serial number 1 2 3 4 5 6 7 8 test value（） 0.9058 1.9928 2.3551 3.7699 5.1836 6.1261 8.3744 9.8971 simulation value（） 0.9058 1.8752 2.5696 3.6331 4.9664 6.4914 8.1556 9.9323 absolute error（） 0 0.1176 -0.2144 0.1368 0.2173 -0.3653 0.2188 -0.0352 relative error（） 0 0.0590 -0.0910 0.0363 0.0419 -0.0596 0.0261 -0.0036 Table 3 Comparison between real values with simulation value on machining volume factors test serial number 1 2 3 4 5 6 7 8 test value（） 14.2510 29.1205 32.2741 33.8378 35.2210 38.5427 39.5514 43.9126 simulation value（） 14.2510 29.3072 31.9664 33.8704 35.5506 37.4730 40.0140 43.4698 absolute error（） 0 -0.1867 0.3076 -0.0326 -0.3296 1.0697 -0.4625 0.4428 relative error（%） 0 -0.0064 0.0095 -0.0010 -0.0094 0.0278 -0.0117 0.0101 Table 4 Comparison between real values with simulation value on diamond grain wear factors test serial number 1 2 3 4 5 6 7 8 test value（） 0.0050 0.0100 0.0060

The TRC plate shows a very coarse dendritic grain structure with an average grain size of 600 mm (Fig. 1a).
It has been confirmed that intensive melt shearing is capable of dispersing the oxide films in the alloy melts, and increases the number of active nucleating particles, resulting in a much finer grain size after solidification.
Both the large number of dispersed MgO particles and the high cooling rate ensure an enhanced heterogeneous nucleation during solidification, resulting in a very fine weld microstructure (Fig. 3).
Liquation cracks at the grain boundaries in the HAZ of the TRC plate.
Yoshida, Effect of grain refiner and grain size on the susceptibility of Al-Mg die casting alloy to cracking during solidification, J.

From the average grain size, the grain number per unit volume (N) can be estimated.
It is reported that the mechanism of grain refinement has three types: a large number of nucleation before solidification; recrystallization mechanism and dendrites fusing during recalescence.
When V=25 m/s, the columnar grains disappear, and Fe7Co3 intermetallic compound forms fine equiaxed grains, as presented as Fig. 3(c).
With the increase of nuclei number of metastable dendrite, under high undercooling, grain coarsening emerged.
According to the experimental results, the grain number per unit volume (N) of Fe7Co3 intermetallic compound in ribbons was estimated by the average grain size.