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In terms of cycles, Stress Life is based on S-N curves (Stress – Cycle curves) and has traditionally dealt with numbers of cycles greater than 105 cycles inclusive of infinite life.
In non-constant amplitude loading, cycles with very small alternating stresses may be present and may incorrectly predict too much damage if the number of the small stress cycles is high enough.
Figure 3 presents a S-N curves of alternating stress versus number of cycles to fracture for diamond (a) and metal bond (b).
For a grain size of 28/20 µm, with the same force parameters of grain and workpiece interaction, the grains will continue to be retented in the bond (figure 7b).
Fatigue life for grain-bond system for 20/14 µm grain size a) b) Fig. 7.

The straining and moderate ECAP temperature caused the cementite lamellae fragmentation and spheroidzation as number of passes increased.
In the past decade, a number of the various sever plastic deformation (SPD) techniques have been used to refine structure of metals and alloys.
The AISI 1045 steel billets were subjected to warm ECA pressing at T= 400°C and to higher number of passes, N = 4, 5, 6 respectively.
The more grown and already equiaxed grains of high angle boundaries, with less dislocations in grains are documented in Fig. 5.
The dislocation substructure in ferrite grains was modified upon dynamic polygonization, however the low angle boundaries are still in ferrite grains.

Ni Grain Boundary Diffusion in Cu-Co Alloys Alexey Rodin1,a, Ainur Khairullin1 1Department of Physical Chemistry, NUST MISiS, 4, Leninsky pr-t, Moscow, Russian Federation arodin@misis.ru Keywords: grain boundary diffusion, Cu-Co alloys, grain boundary structure.
The influence of Co as an alloying element on grain boundary diffusion (GBD) in Cu attracts particular interest due to anomalous GBD of Co in Cu.
Introduction The interest to this problem is connected with anomalous grain boundary diffusion of Co in Cu.
This can not change significantly the situation, because only the saturated solid solution in grains and in grain boundaries can be in equilibrium with a second phase.
Conclusion The study of Ni grain boundary diffusion in Cu and Cu-Co alloys showed that the parameters of GBD did not change with Co concentration.

Grain size measurements were performed using the lineal intercept method according to ASTM standard E112 88, and more than 40 intercepts were counted for each grain size determination.
The initial grain size of as-cast AZ91 magnesium alloy was about 71 µm (Fig. 2).
Fig. 6 shows grain size as a function of calcium concentration.
These intermetallics prevent the grain growth [12, 13].
Initial grain size of as-cast AZ91 magnesium alloy was about 71 µm.

It is proposed that the high strength and plasticity of the ultra fine grained nickel is related to a deformation mechanism involving grain boundary sliding and grain rotation.
Average grain size (D) and number (N) of diffraction pattern spots of Ni as a function of treatment.
Since the number of spots is proportional to the number of grain in the investigated area, it is seen that at 200° � a uniform grain growth begins in the material.
The coarse-grained material shows brittle failure with traces of dislocation sliding on grain surface.
On the other hand, in the UFG structure dislocation sliding across the grains is suppressed due to the small grain size.

Grain boundaries were categorized as Low-Angle Grain Boundaries (LAGB - Σ1), Σ3 grain boundaries, and Σ3-related variant grain boundaries (Σ9, Σ27).
The grain boundary width was 1 pixel.
This is a direct consequence of the reduced number of grains per unit area.
The monotonic variation of grain boundary mass with grain size for both random and Σ3 is evidence that the grain size (D) is a characteristic length scale for the topology of the grain boundary clusters.
The effect of annealing time on the distribution of the number density of the Σ3 n cluster masses (M) is summarized in Figure 4.

From this figure, it is known that output waveforms of grain 1 and grain 2 are closely same output voltage.
Comparing depth of cut 20mm as shown in figure 6 and 40mm as shown in figure 7, it is known that measured results of 40mm are larger output voltage and more the number of output waveforms than results of 20mm.
It is considered that the number of contact abrasive grain with wire is increased with the increase of the depth of cut.
In figure 8, compared the calculated results of AE occurred positon and measured results of actual grain cutting edge position, it is known that the number of cutting edge is increased with the increase of the depth of cut.
Acknowledgment This research was supported by a research grant (Year: 2013, Subject number: R1310) from the Mitutoyo Association for Science and Technology.

Effect of Grain Size on Mechanical Properties of Mg-0.3at.
In contrast, good balance of strength and ductility was realized in fine grained specimens with grain sizes around 2~5 μm.
Mg has an anisotropic hexagonal close-packed (HCP) crystal structure, providing only a limited number of independent slip systems, resulting in low strength as well as poor formability at room temperature [2].
For example, Sandlöbes et al. [7] have shown that a coarse grained (grain size~40 μm) Mg-3wt.
After annealing at 300 oC for 60 min, a fine grained (FG) structure with a mean grain size of 2.13 μm was obtained (Fig. 3(d, e)).

A new approach to solute effect on grain boundary migration Yan Huang BCAST, Brunel University Kingston Lane, Uxbridge, Middlesex, UB8 3PH UK yan.huang@brunel.ac.uk Keywords: Grain boundary migration, solute drag, activation energy, activation entropy, mobility.
According to this model, grain boundary mobility is dependent on solute concentration rather than migration rate.
The interaction is directly related to a tendency of the solute atoms to segregate to the grain boundaries because they will there cause less elastic stresses than in the interior of a crystal, which forms the basis of the solute effect on grain boundary migration.
For a constant solute and boundary interaction energy (E) and a system containing a number of N boundary atomic sites, the free energy decrease due to solute segregation is -NE Xgb and the mean free energy decrease of each atom is -EXgb, where Xgb is the solute concentration in the boundary.
A new approach, based on the fact that solute segregation reduces the free energy of the grain boundary, is put forward to address the effect of solute on the kinetics of grain boundary migration.

Goss grains({011}<100>) are nucleated within shear bands in deformed {111}<112> and{111}<110> grains. {111}<112> grains nucleate in deformed {111}<110> grains and new{111}<110> grains nucleate in deformed {111}<112>grains. {111}<112> grains have an evident advantage both in number and growth rate over α grains, thus the controlling of annealing time can contribute to the increase of {011}<100> texture.
With the increasing of annealing time, as shown in Fig.1 (b), new Goss grains({011}<100>) are nucleated within shear bands in deformed {111}<112> and{111}<110> grains and the number of shear bands is the highest in deformed {111}<112>grains.
Since {111}<112> grains have an evident advantage both in number and growth rate over α grains, when the annealing time increasing to 180s, the area fraction of {011}<100> component drops down to 0, while {111}<112> component is the dominant component.
(2) {111}<112> grains nucleate in deformed {111}<110> grains and new {111}<110> grains nucleate in deformed {111}<112>grains.
Few Cube grains ({100}<001>) are nucleated within shear bands in deformed {111}<112> grains