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Al-5Ti-1B master alloy, an effective grain refiner for commercial pure aluminium and wrought aluminium alloys, is often used also in aluminium foundry alloys to grain refinement.
The beginning of the nucleation temperature progressively moves to higher temperatures as a consequence of increasing the number of nucleation primers.
Grain refiners effect on morphology indirectly.
Eutectic grain size and strontium concentration in hypoeutectic aluminium–silicon alloys.
Effect of grain refinements on the microstructure and thermal behaviour of Mg-Li-Al Alloy.

The grain size could be calculated by Scherrer equation: D=kλ/(β*cosθ)
The FWHM and grain size are shown in Fig. 2.
At 350℃, the grain have maximum diameter is 23.63nm, indicating crystallinity is best.
This result is consistent with FWHM and grain size D analysis.
On one hand annealing made atomic diffuse and rearrangement occurs and provided energy for particles to growth, meanwhile reduced stress,making the adsorption of oxygen near the grain boundary defects sharply reduced and reducing the electron capture trap, thereby the number of carriers increased much.On the other hand made the film grain growth bigger, grain boundary density decreased, weakening the boundary of grain scattering ability, so carriers mobility increased.

The microstructure of crack is shown in figure 2, which shows that the crack originates in bloom surface, and expands along the grain boundary from surface to equiaxed grain zone, and then disappears.
(a) (b) Fig.3 Microstructure of grain boundary in bloom subsurface Figure 3 shows that the pearlite morphologies of grain boundary are quite different in the bloom subsurface of the first heat and the sequence casting heats.
But widmanstatten structure is not found in the bloom grain boundary of the sequence casting heats.
(a) (b) Fig.4 Grain structure of subsurface layer in bloom narrow face The widmanstatten structure in bloom subsurface can reduce the strength of grain boundary, and increase the stress sensitivity strongly.
The larger the grain size of bloom is, the weaker the resistance to stress becomes [2].

Mean grain size was evaluated based on Scherrer formula.
Crystal structure and grain geometry.
Corresponding to this change, coercivity increases with the grain size, and maximum coercivity is 5.97kA·m-1 as its grain size is around 62.0nm.
Then coercivity decreases with grain size.
Larger grains tend to consist of a greater number of domain walls.

Results showed that the measured grain size is in good agreement with the calculated value.
A large number of researchers have studied the static precipitation kinetics of the microalloying element Nb and its effect on the microstructure[1~2].
Under small strain, ferrite grains nucleate at the prior austenite grain boundaries and areas with high density defect, then form repeatively at areas with high stored energy in front of the ferrite/austenite interfaces.
It is suggested that during DEFT nucleation was the dominant factor and ferrite grain growth lost the possibility in space and time because of the impingement of ferrite grain and the pinning of Nb(CN) precipitates.
Results showed that the measured grain size is in agreement with the calculated value.

Results Planting succeeding crops on T-field did not change the yield The data on yields of the four succeeding crops on T-field as well as on N-filed was collected and calculated as follows: Wheat: Wheat Yield /mu= Wheat spikes/mu×grains/spike×weight/grain To obtain the number of wheat spikes per mu, the spike number of randomly selected 1 m2 wheat were investigated and documented.
The number of grains of 20 individual spikes were accounted to calculate the grains per spike (grains/spike). 1000-seed weight was reckoned by measuring the weight of 1000 randomly sampled grains and was further used to calculate weight per grain (weight/grain).
Maize: Maize Yield /mu= Maize spikes/mu×columns/spike×grains/spike×weight/grain The total number of spikes within the randomly selected 1 m2 maize field was accounted to reckon the maize spikes per mu.
To obtain grains per spike (grains/spike), 10 spikes were randomly selected to investigate the number of columns and grains per column. 100-seed weight was reckoned by measuring the weight of 1000 randomly sampled grains.
Beet and Carrot: Yield /mu= plants/mu×weight/plant The plants/mu was obtained by investigating the number of plants in 1 m2 randomly selected field, while the mean of the weight of 10 randomly selected plants was considered as weight/plant.

The AFS grain fineness number 70 foundry sand (WOORI, Korea) and inorganic binder are mixed for 2 min to prepare the UFS containing a 4 wt. % binder.
Results based on the sieve analysis data were presented for both the AFS grain fineness number and the grain size distribution.
AFS grain fineness number was calculated as follows [16]: AFS grain fineness number=Wn×SnWn
A high value of this parameter denotes the existence of a high number of fine particles.
The calculated AFS grain fineness number of the RFS and regular foundry sand are 65.93 and 63.40, respectively, which are analogous to each other.

Exceptional combinations of high strength and good ductility were discovered in a number of materials [4, 5].
The grains on the surface layer are obviously refined and grain size increases gradually from nanostructure on the surface to the coarse-grained center, generating a gradient structure (GS) layer.
The grain size decreased and twin density increased by reducing SFE.
The smaller grains significantly improved the strength of the materials.
The grain size decreased while the twin density increased with decreasing SFE.

The results show that the central area of ingot produced by electromagnetic horizontal casting is composed of uniform equiaxed grains, Some casting defects that usually occur in conventional horizontal continuous casting , such as central crack, shrinkage cavity and porosity are restrained.
The reason why that horizontal electromagnetic continuous casting technique is able to eliminate the central defects could be attributed to several aspects: 1) Electromagnetically driven flow of the molten metal stimulates the primary or secondary dendrite arms mechanical fracture or root fusing [1],which increases the number of nuclei in sump.
The solidification process of alloy take place as isotropic growth of a large number of nuclei in similar circumstance[2,3], as the result, it avoids the “bridge” built up by dendrite arms touch with each other in the central region of ingot that often occurs in conventional casting process.
It not only decreases the microsegregation level of solute elements in the grains but also avoids the macrosegregation of solute elements caused by the ‘bridge” of dendrite arms closure some solute-rich liquid. 3) The forced melt convection reduces the possibility of crystal boundary nonequilibrium compounds precipitation, which plays a function to restrain solute elements segregation. 4) The forced melt convection accelerates the releasing of superheat in liquid sump and strengthens the solid solution of solute elements in grains.
The above two reasons not only can reduce the positive segregation and negative segregation level of solute elements in grains but also can reduce the time and possibility that solute elements form massive IMC at the grain boundary , thus weakens the segregation of solute elements [8,9]. 3.3 The products performance test Various specifications of rods and wires of 1560 alloy were produced by further rolling and cold drawing on 1560 alloy ingot produced by electromagnetic horizontal continuous casting, the testing results show as table 2, It reveals that the quality of products achieves the national relevant quality standard absolutely.

One group of alloys, which are numbered from 1 to 6, are constant Al content of about 6% and various Zn content from 0 to 3%.
Another group of alloys, which are numbered from 7 to 10, are constant Zn content of about 0.4% and various Al content from 0 to 6%.
Because of the largest grain size, alloy 4 have the lowest elongation of 10.5~12%.
Properly stewing before casting would increase the number of nucleating center, and also promote solution diffusion and relieve microsegregation in the meantime.
The grain size increases significantly.