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On the other hand, the size of the specimens has to cover a sufficient number of grains.
However, if the material has undergone a diffusion annealing, which is a standard treatment for superalloys, significant grain growth in the material can lead to a situation where the sample dimensions usually used for upsetting tests only hold a very small number of grains.
Given the usual scattering in the flow stress of as-cast or coarse-grained homogenized material, this scaling is almost negligible.

The grain size of the high-strength glass micro beads varies between 0.05mm and 2.0mm, and grain size gradation is good.
Table 1 The mixture ratio plan and the result of test Test number High-strength glass micro beads Rubber powder volume weight (γ) cohesive force (c) angle of internal friction (φ) deformation modulus (E) infiltration coefficient (K) % % KN/m3 KPa ° MPa cm/s 1 90 10 22.52 0.07 23.6 11.38 4.45E-04 2 80 20 24.04 1.03 22.6 10.68 1.20E-04 3 70 30 25.06 4.13 23.8 8.86 1.40E-05 4 60 40 25.96 6.54 26.3 8.92 8.06E-06 The volume weight and the cohesive force reduce obviously along with the glass micro bead content’s increasing; the modulus of deformation presents the trend of escalation along with the glass micro bead content’s increasing ,and the infiltration coefficient obey the same rule.
Their grain size varies between 1.5mm and 2.0mm.
River sand is the packing material with its specific gravity is 2.78 and its grain size is below 1mm.
Table 2 The orthogonal test plan of three factors and four levels Test number River Sand：lead beads Rubber power Talcum powder Volume weight γ Cohesive force c Angle of internal friction φ Deformation modulus E Infiltration coefficient K % % KN/m3 KPa ° MPa cm/s 1 90:10 5 10 17.57 4.38 33.9 9.674 5.27E-04 2 90:10 8 15 17.33 6.21 31.8 6.352 3.21E-04 3 90:10 12 20 17.3 6.32 32.5 5.667 1.74E-04 4 90:10 15 25 17 8.21 34.7 3.862 9.19E-04 5 80:20 5 15 19.88 3.18 28.8 7.581 1.51E-04 6 80:20 8 10 18.18 2.52 36.4 5.17 8.28E-04 7 80:20 12 25 19.01 5.84 29.7 4.597 1.46E-04 8 80:20 15 20 17.93 4.32 31.6 3.392 4.12E-04 9 70:30 5 20 22.44 3.48 33.6 5.741 2.29E-04 10 70:30 8 25 21.59 3.52 30.9 4.976 2.44E-04 11 70:30 12 10 18.5 2.35 30.2 3.223 1.12E-03 12 70:30 15 15 18.13 2.84 30.1 2.664 8.61E-04 13 60:40 5 25 25.8 0.52 32.6 5.442 4.92E-05 14 60:40 8 20 24.22 0.34 35.3 4.982 9.05E-05 15 60:40 12 15 22.58 0.24 30.4 3.539 3.14E-03 16 60:40 15 10 21.02 0.18 33.6 2.768 7.03E-04 4.3 The Analysis of

The thermocouple was made up of 1Cr11Ni2W2MoV and constantan wire and a hot junction was formed when the cutting action of SG grains damaged the insulator layer around constantan wire.
The temperature of abrasive grits could be used to evaluate the number of active cutting points, contact length and dynamic cutting-point density that would be useful for optimization of grinding wheel topography.
This indicated that the plastic side flow plowing of the 1Cr11Ni2W2MoV stainless steel around abrasive grains increased with the chip adhesion and the steel was extruded to the side of abrasive grains.
The plastic flow of the steel under the abrasive grains led to much scale-shaped debris on the surface and micro-cracks were found on the workpiece surface obviously, as showed in Fig.6(c), which could deteriorate the erosion resistance and reduce the fatigue life of the workpiece.
When ap was lower than 0.03mm, morphology of the surface was clear and smooth, and severe plastically deformed coating layers and a large number of micro-cracks were observed on the ground surface by SEM when temperature was higher than 636 ºC.

However, many researches focus on multiplying this number.
Chemical and physical properties of cement Chemical and physical properties of fly ash CaO 65.0 [%] SiO2 54.2 [%] SiO2 19.0 [%] Al2O3 24.2 [%] Al2O3 4.0 [%] FeO 0.3 [%] Fe2O3 3.0 [%] CaO 4.0 [%] MgO 1.0 [%] MgO 2.8 [%] SO3 3.0 [%] Na2O 0.3 [%] S2- 0.04 [%] TiO2 1.0 [%] Cl- 0.051 [%] K2O 2.8 [%] K2O 0.75 [%] Fe2O3 6.4 [%] Na2O 0.15 [%] C 4.5 [%] Loss on ignition 3.1 [%] Sulphur total 0.1 [%] Specific surface 377 [m2∙kg-1] Loss on ignition 2.7 [%] Mean grain size 20 [µm] Specific weight* 2110 [kg∙m-3] Specific weight 3110 [kg∙m-3] Specific surface* 228 [m2∙kg-1] Bulk weight 980 [kg∙m-3] Mean grain size* 82 [µm] Diagram 1: Distribution curves of used cement and fly ash.
After 24 hours, the specimens were taken out of molds, labeled and placed in water with temperature 20 °C for required number of days.
Viscosity’s reduction could be caused by plasticizing effect of smooth, spherical grains of fly ash.
However, setting time’s retardation is also caused by the surface character of fly ash grains.

Based on a large number of experimental results, the mechanisms of reactive-element effects have been reviewed by several authors [11–14].
Moreover, reactive elements or their oxides played “peg” role in the grain boundary of the alloy.
Researches [3,17] had shown that the grain size of substrate decreased and subgrain defects concentration increased with the yttrium addition, which decreased the critical aluminum amount to form continuous Al2O3 scale.
R.Cueff [3] suggested that yttrium addition reduces the alloy grain size and thus increases the diffusion of cations to the oxidation front, which results in improving selective oxidation.
Yttrium increased the number of possible oxide nucleation sites and it reduced the oxide grain-size, therefore it promoted the selective oxidation of aluminum.

The purpose of this paper is to apply the DIC based estimation of the crack driving force above- to physically small cracks in a coarse-grained ferritic-martensitic steel.
Highlights are the evaluation of crack tip parameters for cracks which are about three grain diameters of size, and the comparison of these results to more classical ways of analyzing such cracks.
The average grain size of ferrite is 32 µm with a volume fraction of 46 % for martensite.
The number of terms N in the Williams series starts from 1 to 10 in an iterative manner, i.e. the coefficients determined in step n – 1 are used as starting values in step n.
The cracks considered in this study stretched across at least three grains with crack tips both in the ferrite and in the martensite phase.

The average grain size estimated by using Scherrer's formula changed from 6.39 to 18.9 nm with increasing filament temperature from 1400 to 1600 o C.
Journal Title and Volume Number (to be inserted by the publisher) microcrystalline, and there is small amount of amorphous phase in the film.
Then, we assumed that the defects located in grain boundaries or amorphous regions.
Filament temperature strongly affected grain size, Si-C bonding configuration and hydrogen content of the films as confirmed by XRD and FTIR studies.
Journal Title and Volume Number (to be inserted by the publisher) [5] Edited by G.L.

As shown in Figure 2a, the typical microstructure of the composite consists of TiC particle, primary α and transformed β phase, which is combined in a mixture of acicular type α phase, β matrix and grain boundary α phase.
It may be due to the existence of elements Mo and Zr in the matrix alloy, which not only reinforce the matrix, but also make the grain size of the composite smaller.
The curve of maximum stress versus number of cycles to failure for the composite is shown in Figure 4 with load ratio of -1 and 0.06, respectively.
Maximum stress as a function of number of cycles to failure with a load ratio of -1 (a) and 0.06 (b).
A crack originated from the flaw within a matrix grain or from the particle, and propagated along several parallel planes.

A large number of works on ternary Ti-Fe-Ni alloys prepared by arc-melting or mechanical alloying have been reported.
It can be seen that the diffraction intensity of Ti, Fe and Ni decreases sharply, and the diffraction peaks broaden obviously after milling 2h, as a result of the lattice distortion and grain refinement.
In the process of ball milling, the severe plastic deformation of the particles occurs due to constant mechanical impact, resulting in a large number of dislocations and sub-grain defects, which speeds up the miscibility between atoms.
Milling time extended to 10h, the flattened particles have partial transformed into equiaxed grain, and the fine grains entirely present to equiaxed shape with uniform size distribution when the milling time extended to 60h.

For multi pass weld, the total cooling time can be calculated by multiplying with the number of weld pass.
In this investigation, the pass number of welding was 14; hence the total critical cooling time at temperature from 300 °C to 100 °C is about 4200 seconds or 70 minutes.
However, the grain structure near the crack is finer compared with the grain structure without crack as shown in Fig. 9 (a).
The finer the grain structure the higher is the hardness value as shown in Fig. 8.
Crack sensitivity of the microstructure was found in the form of columnar grain structure.