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So a large number of research institutes and enterprises is attracted to study it.
This is due to β-Ti grains continue to refine, and the stress and strain of grain continuing to grow with the hit of balls.
At the beginning the grain size is about 35nm.
When the milling time was extended to 70h, the grain size reached equilibrium, and the final grain size is 7nm.
This could be explained by the total number of intermetallics present in the constituent binary phase diagrams.

SEM image (a); needle-shape precipitates inside the α-Mg grains (b); ACJM53 magnesium alloy.
Therefore the corrosion process initiates at the interdendritic regions and progresses towards grain interior.
Thus, these alloys have a large number of micro-galvanic cells and corrosion resistance of sand casting Mg-Al-Ca-Sr alloys is not sufficient.
The corrosion resistance of ACJM53 magnesium alloy is dramatic low due to large number of micro-galvanic cell.
The increase of aluminum content decreases the number of micro-galvanic cells.

The growth of ferrite grains upon reheating in HAZ occurs due to dissolution of the austenite phase and recrystallization of ferrite grains.
The area of the coarse grain zone in HAZ in these deposited coatings has the largest width (0.7 mm).
The width of the large ferrite grain area does not exceed 0.4 mm.
In HAZ of sample No. 3, the grain grew insignificantly.
Austenite interlayers of primary and secondary austenite are comparable to the grain size (up to 0.1 mm).

The effects of the conditioning time and the mesh size of the conditioner grains on the pad surface asperity have been discussed using the proposed evaluation parameters [2][3], in addition to the relationships between the conditioning variables, removal rate, and evaluation parameters.
Conditioning was conducted with #80 mesh diamond conditioner grains.
However, as shown in Figs. 3 (b) to (e), the number of contact regions decreases with the increase in the number of serial batch polishing tests.
The removal rate slightly decreased as the batch number increased, reaching approximately 0.35 mm/min when the number of serial batch polishing tests was nine.
From Figs. 5 (a) and (b), both the number of contact points and the contact ratio slightly decreased with the increase in the number of the serial batch polishing tests.

Vibrational frequency of the test specimen is equal to the input signal frequency and can be used for calculating the number of stress cycles.
The grain size was increased approximately five times by heating the alloy for 15 minutes at 500 °C.
Fractographic studies revealed that the cracks not only propagated with the grain boundaries but also propagated through slip band faults within the grains.
In addition to this it was noticed that grain shape has influence on propagational direction of cracks.
No measurable grain straining was noticed in CuZn37 after 40 million stress cycles at 100 MPa stress amplitude.

Twin roll casting integrates casting and hot rolling into a single operation for the production of alloy strip, representing a paradigm shift of metal sheet production by reducing the number of processing steps to a minimum.
Experimental Properties requirement of aluminium sheet for automotive application are high strength, good formability, weld ability and corrosion resistance and are met largely by a number of Al-Mg alloy (5xxx series) alloy containing Mg more than 2 wt.%.
The microstructure of the as cast Al-3Mg TRC strip (fig. 1(a)) has a grain size of 400 ± 150 mm compared to the MC-TRC processed strip (fig. 2(a)) with a grain size of 200 ± 80 mm.
Enough numbers of the potent oxide particles as nucleation substrates can enhance the heterogeneous nucleation throughout the whole melt volume, resulting in grain refinement as seen in fig. 2.
John, Grain refinement of aluminum alloys: Part I.

In this paper, cold deformation and annealing processes on grains, tensile properties and anisotropies of 5083 alloy sheets were studied.
Alloying with multiple elements such as Mn and Zn as well as impurities like Fe and Si affect solidification behavior of AA5083, as a number of intermetallic phases form.
A Leica DFC295 optical microscopy was used to observe the grain microstructures of different samples and measure their average grain sizes using Image Pro-Plus software.
It is well known that recrystallized grains are formed at specific nucleation sites such as initial grain boundaries, cube bands, transition bands, shear bands and deformation zones around preexisting second phase particles [12].
Chen, The origin of coarse grain structure in friction-stir welded AA5083 after heat treatment, 2009

The average grain size of AZ91D alloy is about 40μm.
The first specimen failure before reaching a maximum number of cycles of 107, and the second one conducts at lower stress level.
The microstructure of as cast AZ91D alloy is composed of α-Mg and β phase, which precipitates along grain boundary.
The large facets are in the order of the grain size in this alloy, whereas smaller features reveal a serrated fracture mechanism.
The facet sizes are nearly the same as, or smaller than, the average grain size.

Si3N4-SiC can be fabricated using a great number of methods, including combustion synthesis (CS), precursor infiltration pyrolysis (PIP), chemical vapor infiltration (CVI), etc. [12-14].
It is well known that porosity, pore size, intrinsic strength of the materials (grain and grain boundary) and microstructure are typical four determining factors for the strength of the composite ceramics [19].
On the other hand, there are a large number of grain boundaries and interfaces in the Si3N4-SiC composites due to the existence of the SiC nanocrystals.
Moreover, the addition of SiC retards the growth of b-Si3N4 crystalline grain.
Kawai, Effect of grain size distribution on the strength of porous Si3N4 ceramics composed of elongated b- Si3N4 grains, J.

It is shown that the grain size grows up from 250 nm to 1-2 µm after annealing at 125°C for 3 h (Fig. 4a), and further to 7-8 µm with some annealing twins being formed in coarsened grains after annealing for 16 h (Fig. 4b).
Similarly, the UFG Cu undergoes an obvious grain coarsening after being uniaxially compressed at 150°C, and the size of many grains reaches ~2 µm (Fig. 4c).
Besides, the typical dislocation arrangement like dislocation cells can be observed in some coarsened grains in this case (Fig. 4d). 3.
It can be seen from Fig. 5 that the plastic deformation micro-features around the fatigue crack tip in the Al6XN steel specimen seem able to be revealed by the ECC technique, and that the major microstructural features around the crack (tip) are dominated by the elongated dislocation cells, which form in great number in the grains near the crack (tip).
The typical dislocation cell structures can be observed in some coarsened grains in fatigued UFG Cu.