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It is obvious that a number of manufacturing defects have effect on the final failure.
Of the emphasis is that these crack propagated from grain to grain along the grain boundary.
In the dimple of fracture there are a number of impurities which contained the elements of Mn and Fe.
For one thing, the crack, called inter-granular crack, evolves along grain boundary direction, and thus very easy to move from one grain to another grain.
There are a number of factors that affect the overall performance.

However, the obtained β-Si3N4 grains are still very fine.
When further increasing of sintering additive addition, some elongated β-Si3N4 grains were observed, indicating well growth of β-Si3N4 grains.
This may due to the fact that the growth of β-Si3N4 grains are via a liquid phase through the solution-diffusion-reprecipitation mechanism, more sintering additive means more liquid phase and hence well growth of β-Si3N4 grains.
Moreover, the number of windows increases with the addition of sintering additive and more windows appeared on big pores.
In detail, below 200μm number of pores in the same average pore size decrease with the addition, otherwise when the pore sizes beyond 200μm.

Nanostructure in the 30 - 50 nm grain size range was formed in the burnished sub-surface layer, and the hardness significantly increased due to the grain refinement.
However there is a general tendency for a saturation in grain refinement by continuing bulk SPD processes [4].
The burnishing parameters were as follows: burnishing forces were 50, 200 and 500 N, the rotation speeds of the specimen were 80, 300 and 800 rpm, the feed speed was 0.01 mm/rev, and the number of the tool passes was one.
We have found that ultra-fine and equi-axed grains in the 30 - 50 nm size range were formed.
Nanostructure in the 30 - 50 nm grain size range was formed in the burnished sub-surface layer, and the hardness significantly increased due to the grain refinement.

Furthermore, under the grain size of 0.54 μm, excepting for the thin film outside of the retained austenite, the overall integral number of weighty retained austenite was also observed to be more than 30%. 2.1.2 Stirring casting.
The depth of the surface gradient layer with higher hardness increased with the increased number of SMRT passes.
The diffusion of metallic Ni led to the formation of a large number of nuclei to refine the grain size of carbides adjacent to the interface.
The greater number of grains per unit volume leads to the more dispersed grains and the smaller stress concentration.
In addition, the finer- grains enable the more grain boundaries, more tortuous and the larger area of the grain boundaries.

In addition to grain size, porosity has also been shown to affect wear behavior [5,6].
Because of importance of binder content, grain size and porosity, the composites were manufactured to possess the similar carbide grains content of 88 vol.%, carbide particles size of 1.0 up to 4.0 µm and porosity level of about 0.4 %.
Melted and solidified metal "clueing" carbide grains together can be observed.
Unprotected grains may be easily detached by subsequent impact.
In addition, there are a lot of coalescences grains and grain - grain interfacial energy may be twice greater than that of grain-binder energy.

The object of research is the process of formation of coarse-grained gear involute profiles.
The vertex angle is determined by the number of passes and camber.
Thus, for a given number of points of the discrete representation n∈1,N is calculated the array of coordinates [xB,yB].
The accuracy of the approximation depends on the number of straight generators disposed at the angle λ to the tool axis.
Ott, Disc cutters and gear cutting machining process coarse-grained gears on CNC [Text], News Bauman MAMI. 1 (2011) 174-177

The T1 phase precipitated in subgain boundaries in peak aged and reverted specimens produce a stronger tendency of delaminating along grain boundary, which is a direct reason for the decrease of anisotropic yield strength.
The T1 phase is liable to precipitate on subgrain boundary, which is due to higher density of dislocations in the vicinity of grain boundary [7].
the grain boundary.
The T1 precipitate phase mainly presented on low-angle grain boundary, which in some extent reinforced the subgain boundary, thereby the expansion of main crack would be predominantly along high-angle grain boundary.
The peak-aged and reverted specimens present a strong tendency of intergranular delamination which weaken the transference of deformation between grains and make a reduction of anisotropy.

Grain size.
Grain size also affects the FCP rate.
The FCP rate increases as the grain size decreases.
The amplitude of the crack growth path deviation is greater for coarse-grain material than fine-grain [15].
Reducing the number of voids and their maximum size can remarkably enhance the fatigue properties of cast Mg alloys.

Introduction In the past a few decades, Ni/TiC composites have attracted much attention from researchers and a number of manufacturing techniques have been developed for their production.
Furthermore, in the field of SHS, the Ni–Ti–C system has been extensively studied by a number of researchers.
In addition, the liquid metals Ni surrounding the TiC grains increases leads to an increase in diffusion path and decreases the driving force for grain growth of TiC and discourages the coalescence of TiC grains from forming larger grains.
This is attributed to the decrease of TiC particles(see Fig.2 ) because grain growth of TiC is an exponential function of the combustion temperature [13].
The results showed that the final products were consisted of TiC phase and Ni phase and the size of the TiC grains decreases with the increase of Ni contents.

The scattering is maximal for elements with high atomic number and from the right side of the periodic table.
Assuming a cubic shape for the grains, the number of atoms perturbed by the surface vs. total number, assuming the interaction length is either 1 or 3 nm.
Assuming a spherical shape for the grains, the perturbation would decrease more rapidly.
Left, Raman spectra of pristine InVO4 films with different grain sizes.
Smaller grains are located in the core.