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The crack would grow easily along the M-A grain boundaries.
Grain boundaries of austenitic are quite active and the grains grow up without resistance.
The grains are finer in CGHAZ of EQ56-5 than EQ56-4 shown in Fg2b and Fg3b.
Through the observation and above analysis .The difference of the fracture parameter CTOD between EQ56-4 and EQ56-5 can be summarized as follows: (1) The CGHAZ microstructure of EQ56-5 contains a large number of low-carbon lath martensites.
Dislocation density of ferrite is low and island M-A distribute in grain boundaries.

In addition, a number of large pores were observed as indicated by arrows in the figure.
In W-(BAg-8), on the other hand, intergranular fracture surfaces were predominant and a number of large pores were observed as indicated by arrows in the figure.
In addition, grain size of W-phases in W-(BAg-8) was generally larger than that in W-Ag or W-Cu, though the reason is not well explained at the present.
Secondly, inferior maximum strength and ductility of W-(BAg-8) to those of W-Cu might be attributed to large pores mostly existing at grain boundaries leading to the grain boundary weakness.
On the other hand, inferior mechanical properties of W-19vol%(BAg-8) composite to those of W19vol%Cu composite are attributed to large pores mostly existing at grain boundaries.

Detailed experimental numbers and conditions are shown in Table1.
Table 1 Experimental numbers and conditions Experimental numbers Electric current pulse (A) Pulse width (US) Gap voltage (U) Frequency (kHZ) Sound intensity (W/CM2) 1 60 90 45 40 300 2 60 30 45 40 300 3 60 15 45 40 300 4 30 90 45 40 300 5 15 90 45 40 300 6 9 90 45 40 300 7 60 15 60 40 300 8 60 15 90 40 300 9 60 15 120 40 300 10 11 60 9 90 15 45 120 40 40 300 300 The morphology of products is measured by JSM-5900LV Scanning Electron Microscope (SEM).
At this moment, adsorbing crystal grains at the surface of nickel microsphere is the main formation pattern.
The size of their crystal grains is very large, and crystallization is obvious.
Increase of the gasification ratio can promote the formation of more fine nickel crystal grains.

It has been already observed by Gholina [5] that a 120o die gives good grain refinement when route A is employed.
ECAP pass number is identified by a number followed by X: one pass 1X, two passes 2X, etc.
The original grain size at the plate center was 3 mm long and 300 mm thick aligned to the rolling direction.
The present observations are in accordance with Kawasaki et al. [6], who reported an abrupt transition in the grain subdivision features after 4 passes in a die 90o ECAP die: the microstructure became more equiaxed, high angle grain boundaries increased their volume fraction and the average grain size was 1.3mm.
The volume fraction of low angle grain boundaries was high, as shown in the grain boundary angle distribution graphics obtained by EBSD analysis.

Multiple slip is then imposed inside the grains, whatever their orientation.
The average grain size was 20µm.
(σ - σ0)/G (σ0 is the initial yield stress), for 20 and 100µm grain size brass.
Multiple slip is then imposed inside the grains, whatever their orientation.
Also, the reduction in the pile-up stress must be related to the low number of dislocations in the new active slip systems.

As the applied stress lowered, the small crack was arrested for a long period (over 106 cycles) at grain boundaries before regrowth, which resulted in a significantly slow growth process.
An electron backscatter diffraction (EBSD) analysis revealed that the crack tip was arrested at grain boundaries.
This explains why the slope of the S-N curve shown in Fig. 2 is reduced after 106 cycles: as the stress level lowers, the number of fatigue cycles consumed during the crack arrest increases.
This process, the unit of which is grain or a group of sub-grains, is entirely crystallographic; it is easily impeded by grain boundaries, and the subsequent process depends primarily on the position of active dislocation sources in the adjacent grain.

The different degree of deformation were investigated by optical microscope, the grain size deformation was used as a data for math modeling of the deformation mechanism.
The width and length of the deformed grain structure were measured by light microscope and micro-hardness of deformed grain was measured by micro-hardness testing machine.
(HV) P1 peripheral 189.425 thickness 196.075 P2 peripheral 188.625 thickness 198.375 P3 peripheral 182.775 thickness 202.950 P4 peripheral 128.275 thickness 153.850 Fig. 4 Microstructure and micro-hardness value Point 1 Point 2 Point 3 Point 4 Fig. 5 The width and length of deformed grain at the point on sample according to show in Fig. 4 The most significant difference between each sample point is the change in grain size and hardness after forming.
This is influenced by the forming number.
The greater deformed grain demonstrate the stress in 3 direction of tool-blank contact region; compression in thickness direction and bi-axial tension in transverse and longitudinal direction.

Transparent amber contains the least number of chemical elements.
It is amorphous, soft mineral (its hardness is 2.2 to 2.5 Mohs numbers), viscous; it can be grinded and polished easily.
Amber is amorphous polymer; it has a number of colours; it produces specific IR spectrum (700 – 1900 сm-1) differing it from other similar resins.
Lower layer of amber-bearing rocks is represented by fine and average-grain dark-gray sand (sometimes it is greenish) and average-grain dark-gray sand with pearl-gray shade.
Well # 3034 (Fig. 4) opened intermountain deposits represented by medium-grained sand with separate grains of glauconite and gravel grains of quartz.

Producing magnesium sheets by conventional hot rolling is expensive due to the large number of rolling passes to final gauge and annealing steps at elevated temperatures between the rolling passes.
In the case of finer grained twin roll cast strips as precursor, an additional grain refiner was considered not necessary by the supplier.
In AZ31, under negative minor strain, continuous bands of very small recrystallised grains are found between large elongated grains.
Only a very small volume fraction of recrystallised grains could be detected at the grain boundaries of the large elongated grain under positive minor strain.
Hildebrand: Metallurgical and Materials Transactions A Vol. 36 Number 7 (2005), p. 1669-1679 [10] V.

Mebed) Keywords: Co-Cu Alloy, Phase Decomposition, X-Ray Diffraction, Rietveld analysis, Grain size, Computer simulation.
Among these mechanisms are spinodal decomposition [11,12], and growth by grain boundary diffusion [13].
(2) (3) where, Gc =Chemical free energy, Estr = Elastic strain energy, c composition, GT =Total free energy, e=Eigenstrain, h is the lattice mismatch, KB = Boltzmann constant, R = gas constant , NA= Avogadro’s number, h = Fourier wave number, L = Length of calculation field in real space, N = Maximum number of h, Q1(h) = Fourier transform of c(r), Qj+1(h)= jth evolution of Q1(h, Vj(h))= Fourier transform of , Dt = time interval.
Fig.1 shows the SEM images of sample S1 (Fig. 1a), Co/Co grain boundaries (GBs) are visible and the grains appear light-grey.
In this case, the Cu solid solution forms the continuous layer separating the Co grains.