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To avoid some of the limitations imposed by exaggerated grain growth and related problems, a number of other consolidation method have been evaluated, such as hot pressing [1], sintering with microwave radiation [2], etc.
Grain size analysis was performed on the digitized SEM photographs using image analysis.
Also, cracks are liable to propagate through the weak coarse grain rather than along the grain boundary.
The pores were observed in the Al2O3 grain boundaries as well as the triple junctions.
The number of pores in the bulk is remarkably decreased compared to the bulk of Fig. 5 (d).

The as-received ZK60 alloy presents a heterogeneous microstructure with coarse grains surrounded by fine grains, as shown in Fig. 1a.
Although coarse grains are still visible after one ECAP pass an obvious grain refinement may be observed.
This peak is quite wide due to the heterogeneous microstructure, because of the fine grains which start to recrystallize at lower temperatures than the larger grains.
It can be noticed that the stored energy decreases with the increase of the heating rate, and reduces with the number of passes.
Conclusions After processing the ZK60 alloy through ECAP by route A the microstructure displays refined grains at increasing number of ECAP passes.

The dislocation density, is related to the flow stress of the precipitate free austenite, , and to the yield stress of the precipitate-free recrystallized austenite,, by: (1) is the driving force for recrystallization (), the grain boundary mobility and the number of recrystallization nuclei per unit volume.
Vol. 10 (1962), p. 789. ]: In the equation, is the grain boundary mobility for the pure material, the Nb concentration in solution, the grain boundary width, the number of atoms per unit volume, the binding energy of solute atoms to grain boundaries and the cross-boundary diffusion coefficient, which was calculated as in [7].
Finally, if the recrystallized grain size, , is known, the number of recrystallization nuclei can be calculated as: .
The transition occurs when the number of particles disappearing due to coarsening is larger than the number of particles forming due to nucleation.
In Fig. 4 (b) the predicted precipitate number density and volume fraction, this latter normalized by the calculated equilibrium fraction, are represented.

Traces of Mg17Al12 still existed, predominantly as irregular shape compounds located mainly in grain interiors.
The number of possible additions is limited and, according to accumulated experimental evidence for high performance alloys, rare or alkaline earth metals are the best choice where the criterion is the formation of highly stable precipitates.
The grains were surrounded by lamellae type morphologies of the Al4Sr phase.
In some grains, small spheroidal precipitates with a dark contrast were detected.
This suggests that Sr reduced the Al segregation effects by confining its presence to grain boundaries.

The middle of these grains contained smaller equiaxial grains that were subjected to dragging.
Columnar grains cause fragmentation during hot forming [11].
Conversely, continuous fine equiaxial rheocast grains were observed at the centre of the cast strip that was dragged by the columnar grains.
Eventually, grain refining can induce fine equiaxial grains near the rolls, thereby avoiding columnar grain formation during the strip-casting process.
This grain formation mechanism is different from what occurs during the pouring of liquid metal, where the grains form in small size at the ingot mould wall.

The Mo-rich phase is precipitated at the grain boundaries at all temperatures.
The white phase is mostly precipitated on the grain boundaries.
The small dark spots inside the grains are inclusions that are oxides of Cr and V.
That is according to Gibbs phase rule, F = C – P + 1 (where F is degree of freedom, C is number of components and P is number of phases).
The maximum number of possible phases in the current 6-element alloy system (Co20Cr20Fe25Ni25Mo5V5) is seven.

The improvement in corrosion resistance could be attributed to the diffusion of Cr allowed by the large number of defects induced by the impact peening deformation.
Fig. 3 also shows the corrosion morphology of the original one, which is characterized by a larger number of cavities, corrosion products, deep corrosion cracks, and unevenness on the surface.
The thickness of the gradient layer was measured to be around 400 μm, and can be divided into a nanocrystalline layer, a fine crystalline layer, a coarse-grained strained layer, and a coarse-grained matrix layer based on the microstructure and the degree of deformation.
The outermost layer of the sample had an extremely fine grain refined to the nanometer level.
The grain size gradually increased to sub-micron, micrometer, and finally coarse grains.

The grit number of SiC in SFAT was #1000, the average grit size about 15 μm.
SFAT contains 65 wt% of #1000 SiC abrasive grains.
The number of the experiments is nine.
Abrasive grains of the surface are covered, and the processing performance of abrasive grains is gradually lost, the abrasive wear will be reduced.
The bonding force of grains is decreased; abrasive grains will be easier removed from the SFAT surface.

Grain is significantly refined during hot compression deformation.
Starting from an initial grain size of 93mm (Fig.3a).
Simultaneously, austenite grain is reduced each pass as Fig.3b-Fig.3e.
The grain size of the last pass (Fig.3f) is almost 50mm.
In this figure, the evolution of average austenite grain size during hot compression is graphically represented against the pass number.

Global climate change affects not only rice yield but also grain quality.
Measurement Content and Method Panicles were harvested from the middle row and the panicle numbers were recorded, when rice had reached harvest maturity.
Grains per panicle, seed setting rate, 1000-grain weight, and theoretical yield were calculated from ten medium-sized spikelets.
Based on the panicle number in each region, the four growing regions could be ranked in the following order: Shanghai > Liaoning > Sichuan/Guangdong.
LN: Liaoning; SH: Shanghai; SC: Sichuan; GD: Guangdong; SN: spike numbers; GP: grains per panicle; SSR: seed setting rate; TGW: 1000-grains weight; TY: theoretical yields; AY: actual yields; The same below.