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Grain refinement generally decreases the thermal conductivity because phonons can be scattered at grain boundaries.
The number of rotations imposed on the disks was 5 turns.
Fig. 4 shows an optical micrograph for the VBM disks indicating grain sizes of several mm.
The flow of the deformation by HPT is traced from the changes in grain shapes as shown in Fig. 5.
(2) The grain size was reduced significantly from mm to µm order by applying HPT

Authors, based on microstructural analysis observed distinct bi-modal grain structure where columnar grains were accompanied by very fine grains without preferential grain orientation.
As per these findings, the growth of epitaxial columnar grains above fine grains was due to segregation of Al3(Sc,Zr) precipitates along melt pool boundary which ultimately results in bi-modal grain structure.
The bi-modal grain structure observed by many investigations can be converted into fully equiaxed grains in the entire sample with nucleation of fine grains on the substrate of Al3(Sc,Zr) [12, 8].
Number density: Fig. 8 and 9 show the number density of Al3Sc due to IHT.
These precipitates could be acting as a substrate for the equiaxed grains and thereby resulting in the fine-grain microstructure.

The grain size of the alloys after annealing was 100 ~ 200 mm.
Experimental Results and Discussion Figure 2 shows the torque and the compression load of Gum Metal as a function of the number of turns during HPT.
Fig. 2 In situ torque and compressive load curve as function of number of turns.
For the 25 Nb alloy, the original grains are slightly deformed and have the curved grain boundaries as shown in Fig. 4 (c).
Such localized shear deformation would process grain refinement, resulting in the very fine grains in Gum Metal.

Ferrite separates out at both grain boundaries and inside the grains.
After hot-forging and air-cooling, the grain fineness number can reach level 7-9.
The ferrite in small blocks effectively divides up the austenite grains, reducing the grain size.
Tab.2 The HRC of developed steel I09-1, I09-2 after hot forging and air-cooling Steel Grade I09-1 I09-2 Heat Number 1 3 1 2 6 HRC 28.7 26.7 30.8 32.6 33.
The grain fineness number after hot-forging can reach level 7 to 9

Fatigue cracks of MB8 alloy initiate principally at surface and subsurface, and propagate along the 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 fatigue crack is propagated along grain boundary as well as transgranular form.
The facet sizes are nearly the same as, or smaller than, the average grain size.
Fatigue cracks of MB8 alloy initiate principally at alloy subsurface, and propagate along the grain boundary.

While plastic deformation sets in within the softer austenite grains, fatigue crack initiation has been observed to occur at phase boundaries at locations where the slip bands emanating from an austenite grain impinge a neighboring ferrite grain [1].
Fatigue cracks propagate along slip bands through the ferrite grains and can be blocked by the next phase or grain boundary.
By using this geometrical information, fatigue damage can be assessed by using the approach of Tanaka and Mura [7] and Chan [8] to predict the number of cycles for fatigue crack initiation.
Crack propagation follows a relationship that was originally proposed by Chan [8] for the number of cycles to crack initiation Ni: , (2) where l refers to the cyclic irreversibility (the part of plastic deformation that contributes to fatigue damage).
By using Dgpl as a fatigue damage parameter, the interaction of fatigue cracks with the grain and phase boundaries as well as with the local stress state (e.g. superimposed residual stresses) can be predicted as a number of cycles Ni to extend the crack by a length increment a.

And then the tartary buckwheat grains were harvested after autumn.
Finally, it was recorded that the yield of seedlings and grain, the thousand grain weight.
Data collection concluded height, branch number, flower number, leaf area, above ground biomass and grain yield at floral initiation period and the beginning of florescence with higher content of rutin suitable for the regeneration of buckwheat seedlings.
According to Table 3, plant height, leaf size, branch, flower number and biological yield and buckwheat production of different varieties varied greatly.
Number of flower clusters and branch number mainly affected tartary buckwheat grain yield. 

Reg ar ding a known network topology, the problem of choosing links and switchers among alternatives different in reliability and cost is settled by a Coarse-grained parallel genetic algorithm, which maximize the network availablity within a fixed budget.
Among them, the coarse-grained model, also known as a distributed model or the island model, is the most adaptable and most widely used genetic algorithm parallelization model. coarse-grained model is the initial population of randomly generated according to the number of processors is divided into a number of sub-groups. various sub-groups are independent of each other on different processors the concurrent execution evolutionary operation, each after a certain evolution-generation between the various sub-groups will exchange certain individuals to introduce the good genes of the other sub-groups, the rich diversity of the various sub-groups, to prevent the occurrence of premature convergence. coarse-grained model less communication overhead, very suitable for running on the communication bandwidth the lower cluster system.
Migration strategy In the various implementations of the coarse-grained model, some choose the best individual subgroups outward "immigrants"; "immigrants" is selected at random.
Some algorithm to replace the population-migrant worst individual; some were replaced by randomly selected using the best individual to move out of the number of / worst individual is replaced by (herein referred to as the best / worst Standards) is the most commonly used, so this is the migration nem = 1 the optimal / worst criteria.
Using literature [7] the method of randomly generated three examples: Each time through the uniformly distributed in the (20, 80) of the random number generator (U (20, 80)) to generate 61 arc length dj.

The results show that morphology and number of ferrite change with the increase of subcritical quenching temperature.
The shape of ferrite evolved from block to thin strip, and the number decreased.
Moreover, temperature of subcritical quenching was lower than that of conventional quenching, which resulted in slow grain boundary migration and was not conducive to the austenite grain growth [2].
The reasons for that are as the following: Firstly, the subcritical quenching temperature is relatively lower, the austenite grain refinement result in the grain refinement of microstructure after subcritical quenching [4].
This paper is supported by Guiyang Municipal Science and Technology Project (Contract Number (2012101)2-5, (2012207)03), and Guizhou Industrial Research Project(Contract Number〔2014〕3018).

The dynamic recrystallization and grain growth will occur mainly in the hot forging process and it has important influence on the grain refinement.
Fig.1 The distribution of average grain size after simulation Fig.2 Optical micrographs of measured points Fig.2 shows the distribution of average grain size in longitudinal sections after upsetting process.
Furthermore, the velocity of nucleation is faster compared with that of grain growth with larger deformation and lower temperature so that the grain is finer and more uniform.
However, lower dislocation density and distortion energy with smaller deformation and lower temperature leads to a lower number of nucleation on the blade rabbet and damper platform.
Fig.7 shows the average grain size of the five feature points in Fig.6.