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Concerning the FSP of metal matrix composites, the method for inserting the reinforcing phases in the matrix is an important experimental parameter, and a number of different procedures for their insertion have already been presented in the literature.
Since FSP had originally been developed as a way to bring about microstructural modification such as grain refinement due to dynamic recrystallisation [17, 18], the grain size in the FSP C-Mg composite was observed on an etched sample, and compared with the Base Material (BM) and FSP sheets of AZ31B without C reinforcement.
FSP moreover leads to the occurrence of a slight grain refinement, and this effect is still much stronger in the composite (Figure 2(c)).
This observation is consistent with reports on FSP composites in literature [1, 18, 19], and it is usually ascribed to the pinning effect of the reinforcing phase on the grain boundaries.
This lower grain size is expected to improve the mechanical properties of the FSP composite compared to the FSP alloy.

Internal gettering is dépiéger metallic impurities their initial interstitial positions and then have them distributed to trap sites (oxygen precipitates, grain boundaries,) where they will be neutralized [4].
The depth distributions of manganese (55Mn) and chromium (52Cr) diffused in the same grain of silicon wafers crystallographic growth treated at different temperatures for 90 minutes are respectively, shown in Figures 1.
In this work, it has been mainly applied to measure the interstitial oxygen concentration ([Oi]) present in the various silicon wafers by measuring the amplitude of the peak corresponding to the SiO bond that absorbs photons associated with the number of wavelength (~ 1106 cm-1).
Austad [12] is that the impurities that are in the spread platelet grains under the effect of the temperature to the grain boundaries, precipitation of these impurities results in an increase of electrical activity.
The electrical activity can be characterized in terms of resistivity, it will be uniform within the grains, but it will change abruptly at the grain boundaries due to the high concentration of impurities.

Frequency characteristics of ultrasonic signals In general, ultrasonic wave velocities change as the material degrades due to ultrasonic scattering and dispersion by the grains, extraction and micro void.
It can be seen that the grain size became larger with increasing degradation time.
Ultrasonic attenuation measurements are also influenced by the degradation time and a small number of large grains may change the attenuation coefficient significantly.
Ultrasonic signals are strongly affected by the material microstructure including grain size, extraction of grain boundary and surface roughness.
This is due to the increase in the attenuation of the high frequency components by coarse grain and extraction of grain boundary etc, in the degraded specimens.

The excellent mechanical properties including better creep and oxidation resistance are controlled by the grain size and secondary dendritic arm spacing of primary phase, as well as the morphology and distribution of γ′ phase inside the γ matrix [2-4].
The average grain size and volume fraction of γ′ phase were analyzed statistically by the software of Image-Pro Plus 6.0.
Morphologies of γ′ phase in dendritic core after aged at 1000 ℃ for different time (a) 30 min; (b) 60 min; (c) 120 min and (d) 240 min The time evolutions of grain size and volume fraction of γ′ phase are presented in Fig. 4.
Consequently, both the nucleation rate and actual nucleation number are increased.
Apparent grain refinement occurs as for higher cooling rate and the secondary dendritic arm spacing reduces accordingly, which contribute to the decline of the size of eutectic phase.

Grain size was determined by a mean linear interception method.
The XRD data (collected by Rigaku MiNi Flex II with Cu-Ka radiation) matches with the International Centre for Diffraction Data (ICDD) file number 00-036-0153 which the symmetry was identified as rhombohedral phase.
It was found that the average grain size of ceramic was about 0.94 µm.
Histogram graph in Figure 2(b), shows a mono modal grain size distribution, suggesting that the ceramics had uniform distribution where average grain size was in a ranging of 0.90 - 0.99 mm (see Figure 2(b)).
This result also revealed that the obtained ceramic had a fine grain.

The wire specimens were sheared, and a number of the sheared specimens were further trimmed by succeeding shaving processes.
The average grain size of the specimen, 7.3 mm, was much smaller than its diameter.
It could be assumed that the effect of grain size on inhomogeneous material flow was not significant.
Chan, Geometry and grain size effects on the fracture behavior of sheet metal in micro-scale plastic deformation, Materials & Design. 32 (2011) 4738-4746
Lin, Influence of grain size and temperature on micro upsetting of copper, Proc.

It could be found SiC coatings were smooth and dense in the four deposition temperature, but there are all exist a number of holes and micro-cracks on the surface.
As the temperature increases, the grain of the SiC showed a gradually increasing trend.
In general, at elevated temperature the deposition rate of SiC become faster which result in the grain grow up and the intension of the coatings improved gradually.
But if the temperature is too high, the grain size will be crassitude which will affect the strength of the coating surface.
With the increase of deposition temperature, the grain of the SiC is increased

Of particular interest is the excellent bonding between the B4C grains and the in situ formed TiB2 grains.
The growth of the B4C matrix grains seems to be inhibited by formation of TiB2 particles.
It seems that it is attributed to the high density and the fine grained microstructure shown in Fig.4 (b).
The composites exhibited a composite microstructure where TiB2 particles were dispersed uniformly in a fine grained B4C matrix.
Acknowledgements This work was supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (HIT.NSRIF.2008.37) and the National Natural Science Foundation of China under grant number 50605016.

The size of the grains of SiC source material was in the range of 10-20 µm.
We observed also the influence of Ce dopant on the SiC source material - namely, the inhibition of the growth of SiC powder grains (lack of source front evolution).
This fact was very advantageous because it allows to avoid polycrystalline grains formation at the crystal edges, which were in close contact with graphite ring.
Structural defects in the form of low angle grain boundaries were observed.
The number of micropipes in the used 6H-SiC seed was maintained in 4H polytype.

From Fig.3, it was found that grains of LNKN6/50 ceramics possessed regular geometrical configuration, and the grains were compacted tightly; only a few pores were observed on the surface of LNKN6/50 ceramics.
Furthermore, the average grain size of MnO2 doped LNKN6/50 ceramics is larger than that of pure LNKN6/50 ceramics.
It is suggested that the addition of MnO2 could promote the growth of grains of LNKN ceramics.
On the other hand, MnO2-doped can also improve the growth of grains and decrease the sintering temperature of LNKN ceramics.
Xiao: Chinese Patent, Applied Number: 200510020230.5 [9] Y.