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But the number of heating lines has a significant effect on the stress-strain curves, where the heating-lines number increasing results in stress amplitude decreasing.
Parameters of stress-strain curves with different spacing and lines number are shown in Tab.3.
The optical micrography of zone A, B and C are shown in Fig.10, where martensite volume fraction, transformed from austenite, and the average diameter of grains from Zone A to C increases gradually.
Based on the Eq. (3), it can also find that the increasing of diameter of grain of material induces the increasing of strain hardening exponent () in Fig. 7 (b).
The hardening coefficient and strain hardening exponent are related to the martensite volume fraction transformed from austenite and grain diameter after laser forming.

It can be seen that after annealing, the grains presents uniform equiaxed grains with an average size of about 35 μm.
Fig. 7 Strain amplitude as the number of cycles Fig. 8 Stress amplitude as the number of cycles Similarly, the data of the plastic strain amplitude of all the cycles was recorded.
Fig.7 shows the development of the plastic strain amplitude versus the number of cycles.
It can be found that as the cycle number increases, the plastic strain amplitude of the samples decrease evidently before fracture.
Fig.8 presents the development of the stress amplitude versus the number of cycles.

SiC acts as a grain refiner.
The following two factors may contribute to the grain refinement.
The number of grain nucleation sites increases with the distribution of SiC particles in the melt.
As a result, formation of finer grains takes place due to enhanced grain refinement.
As the weight percentage of SiC particle increases, the number and size of pits on the worn surface decreases.

Aluminum grains were formed initially during casting.
Between the dendrites there were a large number of small particles (0.2-5 µm in size): Mg, Si, Ca, F, and less Cl, Na, Mn, Fe, in addition to traces of K and P.
Electron back scatter mode with atomic number contrast in the SEM.
SIMS analysis indicated that the Ti-concentration was from 0.008-0.08 wt% in the grains below the surface.
Small K and P rich particles (probably AlP) were found close to the center of grains.

Grain size as low as 500 nm could be achieved.
It yields ultrafine-grained powders of metastable crystalline or amorphous phases [14].
Addition of small amount of graphite to the powder mixture shall be advantageous since graphite reduces grain size during consolidation by restricting grain growth.
So, the grain size decreases with increase in milling time.
With more number of these cycles the grain size is finer and the alloy is more homogeneous.

The composition analysis and the average grain size of tungsten carbide have been rechecked.
C∝= 2NLWC2NLWC + NLCo (2) Where C∝ is Carbide contiguity, NLWC and NLCo are the average number of intercepts per unit length of test lines with the traces of carbide-carbide grain boundaries and carbide-binder interface.
There were small differences in grain size between WC-12Co and WC-14Co.
Three types of WC-Co cemented carbide used in this work had similar grain size.
[13] ASTM E112-12 “Standard Test Methods for Determining Average Grain Size”

However, these two parameters do automatically not relate to the microstructural parameters, such as grain size and microcrack statistics.
A number of attempts have been made to establish the micromechanical basis of the parameters in the Weibull theory.
The curve of microcrack length versus its number of microcracks is given to fit Equation (2a) shown in Fig. 1.
Considering that the computer code RFPA is a 2-dimensional model, V, as an elemental volume, is assumed to be the same as the grain size D and V0 is assumed to be grain size.
The specimen is assumed to undergo Fig.1 Curve of crack length vs number of crakcs for Grey marbles 0 20 40 60 80 100 120 0.026 0.052 0.078 0.104 0.13 0.157 0.183 0.261 Crack length(mm) Number of cracks Grey marble Power (Grey marble) ( ) 068.2 0522.0 � = aagplane strain compression.

The measured densities and grain size of the ceramic samples were found to range from 5.79-6.03 g/cm3 and 0.5-1.6 µm, respectively.
Introduction It is well known that a number of solid solution systems in ferroelectric ceramics are scientifically and technologically important.
Therefore, a number of non-lead material systems have been investigated in order to to find suitable replacement for lead-based compounds.
Although a number of dopants have been used to modify properties of BNT ceramics [13-15], the solid solution Bi0.5Na0.5(Ti,Zr)O3 have not yet been investigated in detail.
The average grain size ranged from 0.5-1.6 µm and increased with increasing Zr content.

It is argued that the appearance of the {311}<136> recrystallization texture component can be attributed to oriented nucleation in the vicinity of grain boundaries between slightly misoriented rotated cube grains.
Grain oriented (GO) electrical steels are employed as magnetic flux carriers in power transformer devices.
As it was pointed out already by Homma et al. [8] {311}<136> oriented nuclei appeared in the grain boundary area of a 70% cold rolled and partially recrystallized bi-crystal, which was composed of two slightly misoriented {001}<110> rotated cube grains.
In order for the present SPD approach to be successfully implemented in an industrial process, a number of issues need to be addressed.
Hutchinson (KIMAB, Stockholm, Sweden) for number of inspiring discussions on the issue of texture development in general and in electrical steels in particular.

As shown in Fig. 1(b), grains in topmost surface present equiaxed grains and average grains size is refined to 10 nm.
As shown in Fig. 2(e), a large number of coarse grains can be observed in shear deformation region.
However, as shown in Fig. 3(e), when annealing temperature rise up to 650℃, a large number of sub-micron grains emerge.
The average grains size in the outermost surface grows up more than 200 nm.
In order to clearly observe the grains size and microstructures of refined grains, attention is therefore focused on TEM observations.