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The morphology (SEM) of sintered sample showed a fine grained microstructure with equiaxed grains.
The Nd and La had lower atomic numbers in all of the 17 rare earth elements, thus the Nd2O3 and La2O3 could be seen as typical light rare-earth oxides which show higher basic.
Our previous (Table 2) study on melting behaviors of SiC and a series of RE2O3 (mole ratio,1:1) had shown that the melting temperatures raised with the increasing of the atomic number of rare earth elements (from La to Er and Y).
While the overall grain sizes remained very fine for all compositions investigated, it can be noted that the grain sizes decrease with the increase of additive cationic radius.
Apart from crack deflection, grain-bridging due to the weak grain-boundary may also play a significant role in the toughening of LPS-SiC ceramics (Fig. 3b).

The cause of this agglomeration is assumed to be grain boundary grooving, driven by the difference between the interface energy and grain boundary energy.
Firstly, one can observe that the agglomeration of NiSi is accompanied by abnormal grain growth: the fraction of grains that exhibit the axiotaxy texture increases, both during agglomeration, as well as during prolonged anneals of thick NiSi films [7].
Figure 2: Effect of grain morphology on the interface matching.
In summary, the complex epitaxial texture of CoSi2 was found to originate from a limited number of axiotaxy texture components.
In the case of Co/Si(100), it was shown how a complex microstructure consisting of a large number of epitaxial components could be understood from the underlying axiotaxy texture.

Furthermore, grain refinement occurred due to dynamic recrystallization.
It was found that the number of Al2Ca was much larger than that of Al-Mn-based IMCs, indicating that the dark areas observed in Fig. 1 consisted mainly of Al2Ca.
Figure 4 shows the microstructure in the SZ, consisting of fine equiaxed grains whose average grain size is 5.6 μm.
Furthermore, the number of Al2Ca was less in the FSPed specimen than in the as-extruded one as seen in Figs. 1 and 4.
In general, the hardness increases with decreasing grain size, namely strengthening effect of grain refinement.

The AFM observation shows that the average grain size of LaB6 crystallites is less than 23nm.
Numbers of defects on surface decreased firstly then increased afterward.
Number of defaults is decreased with rising of the substrate temperature.
Average grain size of LaB6 film that deposited at 400℃ is the maximum.
The surface roughness of LaB6 enlarged with grown of grain size.

The grey particles distributed at grain boundaries or within grains are AlLi compounds (marked as B).
Among them, the grain size of alloy 1 is not uniform and the average grain size is 32.30 μm.
The average fine grain size is 6.66 μm, while the average coarse grain size is 38.60 μm.
The increase of grain number in per unit volume also leads to the gross deformation of alloys dispersing among more grains and the stress distributing more uniformly, thereby the ductility of the as-extruded alloys improves.
The as-extruded Mg-14Li-3Al-0.6RE alloy obtains the finest grain and the average grain size is only 4.28μm.

mm ≥ 549 – ≥ 35 196÷343 ≥ 5 stable Furnace heating, average values for pipes Dp x Sp = 16х1.5 mm 642.7 – 46.1 247.2 10.8 stable * Note: number of single grains is specified in brackets 100 мкм 100 мкм 100 мкм 100 мкм 100 мкм 100 мкм 100 мкм 100 мкм Fig. 2.
Microstructure of metal of the pipes after treating: a – I = 420 А, U = 58 В, grain size 10 and 9 points and deformed non-recrystallized grains, = 679 MPa, = 434 MPa, = 37.2%, = 368 MPa; b – I = 430 А, U = 60 В, grain size 10 and 9 points and deformed non-recrystallized grains, = 703 MPa, = 472 MPa, = 32.4%, = 296 MPa; c – I = 500 А, U = 70 В, grain size 10 and 8, = 603 MPa, = 282 MPa, = 51.8%, = 204 MPa; d – I = 550 А, U = 75 В, grain size 10(7) and 8, = 597 MPa, = 274.4 MPa, = 53%, = 191 MPa; e – I = 600 А, U = 77 В, grain size 10 and 9, = 604 MPa, = 243 MPa, = 53.9%, = 149 MPa; f – microstructure of metal of pipes after furnace heating, grain size 10 and 8, = 637 MPa, = 358 MPa, = 51.5%, = 304 MPa; g – I = 760 А, U = 105 В, grain size 5 and 6(7), = 580 MPa, = 220 MPa, = 60%, = 181 MPa; h – I = 800 А, U = 105 В, grain size 4 and 6, = 553 MPa, = 206 MPa, = 64%, = 144 MPa.
It should be noted that at the heating mode with a current of 500A, rather big number of sections (about 30-40%) with grain size smaller than 10 points is observed in a microstructure of metal (Fig. 2c); that confirms underheating of pipes in the course of heat treatment.
The microstructure of metal of heat treated at current 550A and 600A consists of austenitic grains of 10,8 points and single grains of the 7 points (Fig. 2d and 2e), which size is rather far from admissible limit (not larger than the 5 points).
In a microstructure of metal of pipes heated at the current of 650A, 6 points grains which size is close to maximum permissible 5 points are observed besides austenitic grains of 8,7 points.

Due to the large number of solutes and wide solidification temperature range of 7075 aluminum alloy, dendrite non-equilibrium eutectic microstructure will produced during solidification.
The second phase along grain boundaries contained 61.36wt.% Al, 20.24 Zn, 9.99 Mg, and 8.41 Cu.
In the as-cast morphology, a large number of Mg (Zn, Cu, A1)2 phases were connected along the grain boundary.
Al2CuMg Fig. 6 EDS analysis of non-equilibrium eutectic structure of 7075 Al alloys Fig. 7 X-ray diffraction pattern of 7075 Al alloys Because of the first-order homogenization, there are still a large number of coarse non-equilibrium eutectic phases along the grain boundary.
There have still been some coarse Mg (Zn, Cu, Al)2 phases along grain boundaries.

There is a number of advantages of the in-situ method compared to the ex-situ one.
It is also seen that the addition of Nb is increasing the size of carbide grains.
Furthermore, the effect of high torch velocity is visible in the shape of grains.
The reason is that the addition of Nb can decrease the number of carbides because of forming of (Nb, Ti) C.
On the other hand, the number of agglomerations can decrease hardness due to decreasing homogeneity distribution of carbides.

Texture evolution depends on the number and type of slip and twin modes active in each crystal.
Grain shape can evolve differently from grain to grain depending on their anisotropy and orientation and on average grain shape can depend on pass number and ECAE route.
Grain stress and interactions with neighboring grains change with grain shape, which in turn, impact grain re-orientation by changing the number and type of activated systems.
Depending on the route, pass number, and material, there are certain conditions in which grains are calculated to become severely distorted, for example, after three to four passes of route A [32].
The number below each pole figure indicates the number of ECAE passes and the letter indicates the route.

After solution treatment, the distribution of second phase decreased and after aging, there are many second phases precipitated along the grain boundary and inside the grains.
After aging, there are many second phases precipitated along the grain boundary and inside the grains and the aging microstructure are relatively uniform.
In the early stage of immersion, large numbers of hydrogen bubbles are evidently observed arising from the surface of as-cast specimens, indicating a fast rate of hydrogen evolution due to the reaction of Mg matrix with the corrosive electrolyte, while the numbers of hydrogen bubbles arising from the surfaces of the solution treatment and aging are comparatively fewer.
The second phase is expected to act as a barrier when there is a small grain size.
And after aging, there are many second phases precipitated along the grain boundary and inside the grains and the aging microstructure are relatively uniform.