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The grain refinement occurred where grain size was about 10-20 µm.
The relationship between surface crack length, 2c, and number of cycles, �, for the as-cast and FSPed specimens is illustrated in Fig.6.
(a) and (b). 1mm (b) (a) 1mm (c) 500µµµµm Crack growth direction consists of coarse grain structure of the matrix (α-Mg phase) and eutectic β-phase (Mg17Al12) distributed at the grain boundaries.
Intense material flow can be seen in the stir zone (Fig.9(b)) and grain refinement occurs in the matrix, resulting in homogenous equiaxed grain structure with the average grain size of approximately 10 µm (Fig.9(c)).
The crack growth resistance was also enhanced by FSP due to the grain refinement and hardness increase.

After welding, grain refinement can be observed in the stirring zone.
The grains in the stir zone were 1–6 μm in size.
Because the base metals were produced using press rolling, the grains were slender.
The base aluminum alloy had a hardness of approximately 100 Vickers Pyramid Number (HV).
Grain coarsening resulted in a decrease in material hardness.

The microstructural observation after DPRM showed that the equiaxed austenite grains are observable within a small liquid matrix.
If enough wetting is achieved along the grain boundaries, the initial shear during the forming process may cause the grains to flow pass each other, and the semi-solid slurry to flow thixotropically.
Currently, there are a number of methods that can be used to achieve a globular microstructure, such as the cooling slope, mechanical stirring, magnetohydrodynamic stirring (MHD), direct partial re-melting (DPRM), etc. [5-7].
The eutectic carbides, formed on the grain boundaries during the solidification of the liquid phase.
The microstructural observation after DPRM revealed that the equiaxed austenite grains with some non-dissolved carbides are observable within a small liquid matrix.

Grain size distribution for the fine sand and the coarse sand are shown as Fig.1 and Fig.2.
Grain size distribution for the fine sand Fig.2. 
On the condition of bentonite, adopt the grain ingredient for coarse sand is 30%; on the condition of bubbles with bentonite, adopt the similar grain ingredient with FIR 20%.
Patent number ZL 200620175127.8, 2008/1/09, CN200620175127.8
(Pantent application number 200910223854.5, Pantent publication number CN 101717221 A)

Simulation for the variation of the number of active grinding points was also made for non-uniform wheel topography.
However, the chip pocket size is mainly determined by the protrusion height of the grain.
The number of active grinding points tends to be stable on the level of 8 after the 6 th calculating iteration.
For resin bonded CBN wheel with grit number 40/45, the synthesized parameter El should kept at 0.42 J/mm 2.
The number of active grinding points depends not only on the dressing process, but also on the grinding parameters.

Large number of micrographs from different regions of the TEM specimen was used to improve the statistical significance of the results.
The glassy phase is homogeneously distributed at the grain boundaries.
According to the grain size distributions of the crept samples, no evolution in the grain size was detected, within the experimental uncertainty.
TEM analysis is not capable for conclusive results due to the limited number of different grains that can be analysed.
In all specimens, the average grain size was 45 ±5 nm.

The results show that a minor additive of Cr can refine effectively the secondary dendrite arm spacing and decrease the number of coarse interdendritic structures.
The results show that a minor additive of Cr can refine the secondary dendrite arm spacing effectively and decrease the number of coarse interdendritic structures.
Therefore, Cr element can refine the growth of the as-cast grain effectively to some extent.
Al–Mg alloy engineered with bimodal grain size for high strength and increased ductility[J].
Effect of minor Cr, Mn, Zr, Ti and B on grain refinement of as-cast Al-Zn-Mg-Cu alloys[J].

The submerged condition helps to mitigate excessive heat accumulation, thereby minimizing grain growth and promoting finer grain refinement.
From the analysis of Submerged Friction Stir Processing (SFSP) based on the number of passes, it is evident that the mechanical and microstructural properties of the processed material improve with an increase in the number of passes.
In conclusion, the number of passes in SFSP is determining the quality and performance of the processed material, with multiple passes generally leading to superior material properties, especially in terms of grain refinement and mechanical strength.
Defects, such as micro voids or inclusions, may appear as dark spots near grain boundaries.
Atomic Percentage (At%): This reflects the count of atoms for each element relative to the total number of atoms detected, giving insight into atomic distribution.

The value of microhardness for HPT discs varied from 4.3 to 5.0 GPa and 5.0 to 5.5 GPa depending on the number of rotations, n, (0.5-10.0), in the centre and the edge of discs, respectively.
In the structure, especially after ECAP at 400˚C some grains are visible, but many grain boundaries are poorly defined.
Thus, in the case of ultrafine grains, the required spatial quasi-isotropic compensation of elastic stresses caused by Rmartensite is attained outside a single grain, but in a group of neighbouring grains.
Temperature dependencies of electrical resistance ρ (T) of Ti49,5Ni50,5 (a) and Ti50Ni49Fe1 (b) as-processed by HPT at room temperature for a rotation number n=5.
For weakly invasive osteoplasty we designed a number of new SME devices for treating fractures of the femur neck [8].

Coefficients for bulk and grain-boundary diffusion of tin in CuSn and Nb3Sn as a function of composition and temperature, and information about grain sizes, reaction kinetics, thermal expansion and volume changes on reaction, have been obtained from the literature.
It was hoped that these models might ultimately be integrated with production, and that a large number of heat treatment options could be screened, so rapid calculation was preferred.
During the reaction, the condition of an element is described by the number of moles of tin within the bronze matrix of the element and the number of moles of unreacted niobium remaining; using the appropriate geometrical factors, the average layer thicknesses and matrix compositions are also calculated for each element at each iteration.
Grain boundary diffusion is expected to make a very significant contribution [4] - the temperature-dependent diffusivity is calculated using the bulk and grain boundary diffusion data reported by Farrell et al. [5].
Gust: Fundamentals of Grain and Interphase Boundary Diffusion (John Wiley and Sons, Chichester, England 1995)