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The grain size distribution of quartz sand and FNS is shown in Fig. 1.
Grain size distribution of quartz sand and FNS.
The angular sharp edges of the FNS grains only give a small effect on flexural strength, resulting in similar flexural strength with reference mixture as mentioned above.
Acknowledgement The authors would like to thank the Vlir-Uos, Belgium for providing the financial support to this research project (The South Initiative 2020-2021) with contract number: ID2020SIN281A101.

For instance, Yanushkevich et al. [2] reported that an increase in the cold-rolling strain accelerates the recrystallization kinetics, which results in much finer recrystallized grains.
The fraction of recrystallized ferrite grains was estimated using Eq. 1 [6]: × 100 (1) where Hw is the Vickers hardness of the entire specimen, HNR is the Vickers hardness of the as-cold rolled specimen, and HR is the Vickers hardness of the fully recrystallized specimen.
Thus, it is likely that a large number of dislocations was generated by martensitic transformation during cooling after hot-rolling, thereby accelerating the progress of ferrite recrystallization of specimen M.
Weertman, Dislocations, grain size and planar faults in nanostructured copper determined by high resolution X-ray diffraction and a new procedure of peak profile analysis, Acta Mater., 46 (1998) 3693-3699

Experimental conditions Macro strain (µ) Experimental conditions 0 643 1251 1611 1902 2590 3173 3356 3496 Incident beam size 0.05 mm × 0.5 mm Collimator size 0.05 - 2 mm × 1.0 mm Number of measurement point 3 points (0.1 mm step) Measurement time at one condition 15 min/point (total: 45 min) Figure 2.
Some oscillated (hkl) planes correspond with any slip plane, {111}, {112}, or {123} for α-Fe or {111} for γ-Fe (see in e.g. [12]), suggesting that the formation of dislocations began on local grains which were specific planes.
Other possibilities for oscillation of the lattice strains are stress in a direction other than the loading axis, or rotation of grains by tensile loading.
This result could support the existence of the rotation of grains despite being in the elastic deformation zone.

Whereas, the interface of nano-powder appears a large number of soft and hard aggregations in the atmospheric environment due to volume effect, surface effect, quantum size effect and so on in the nanoparticles, this leads to poor performance of the nano-powers.
It is clear that the dispersant dosages on the crystallinity have not influence, the diffraction peaks with high intensity show the high crystallinity of the powders, which can be attributed to the use of dispersant OP-10 that it only adsorb on solid surface and reduce the surface tension, restrains the grain grow up.
Grain size effects on dielectric properties of barium strontium titanate composite ceramics[J].Materials Research Bulletin, 2013,48(3):973-977
Hydrothermal synthesis ofBaTiO3 from different Ti-precursors and microstructural and electrical properties of sintered samples with submicrometric grain size[J].

The brighter particles are related to phases having elements with high atomic number.
Apart from a few large bright particles, smaller particles are present in the bulk as well as decorating the grain boundaries.
For a slower cooling rate, such as 1 K/min, there are more particles present in the matrix as well as along the grain boundaries (Fig. 3(a)).
It is well known that during the cooling of an Al-Zn-Mg alloy after solution heat treatment, precipitation of η-MgZn2 phase mainly occurs via heterogeneous nucleation on dispersoids and grain boundaries [7].

The crushed rock layer with a specified grain size beneath the pavement layer is composed of a poorly-graded open coarse rock matrix.
The depths of the open grain crushed rock and pavement layers are H and H1.
Usually, it is assumed that local thermal equilibrium exists between the earth fill or crushed rock and the air and that Darcy’s law can be satisfied approximately as long as the Prandtl-Darcy number of crushed rock layer is larger [19].
The average grain size of crushed rock matrix is 6—8 cm.

A number of different composite materials have been fabricated into nozzle inserts, thrust chamber throats, etc.
The Nextel 720 fiber has both a secondary phase and elongated grains incorporated into its microstructure.
The mullite (55 vol%) is present primarily as needles surrounding the Al2O3 grains (45 vol%).
However, the recent work of Göring and Schneider [3], illustrated that at temperature of 1300o C and above grain growth of Nextel 720 resulted in the decrease of the strength in heat treatment times of 2h.

Analysis of ZnAl type alloy microstructures with different additives has been thoroughly covered in a number of works [1-3,5-8], though less is known about the Al content in castings made of ZnAlCu after gravitational cast, and also about the influence of annealing on the morphology of the microstructure and hardness.
The usual mechanical grinding and polishing with diamond wax and polishing belt with grains 3 and 1 μm and with a very fine finish strap and OP-AN liquid suspension were used to prepare the samples for metallography.
Heat treatment eliminated the dendritic microstructure of ZnAl27Cu2 alloy, grains of light phase α and dark eutectoid composed of phases α + η and phase ε were observed, Figs. 18 and 19.
Fig. 15 Microstructure of ZnAl27Cu2 Fig. 16 Detail of phase ɛ in ZnAl27Cu2 Fig. 17 Lamellar eutectoid in detail with white grains in ZnAl27Cu2 Fig. 18 Microstructure of ZnAl27Cu2 after heat treatment Fig. 19 Microstructure of ZnAl27Cu2 after heat treatment Fig. 20 Particles based on Fe in ZnAl27Cu2 after heat treatment Fig. 21 Microstructure of ZnAl40Cu2Si2 Fig. 22 Microstructure of ZnAl40Cu2Si2 ZnAl40Cu2Si2 alloy Microstructure of the alloy with the highest Al content of 40 % alloyed with Cu and Si had dendritic morphology in the cast condition too, Fig. 21, 22.

In these studies, the reduction in coating porosity after heat treatment is attributed to diffusion – driven mechanism or sintering mechanism, which enhance cohesive bonding between particles and thereby reduce the number of defects within the coating [6, 7, 8].
The recrystallization process may have caused the change of elongated grains to globular.
Stresses accompanied by this change in substrate grain shape explain the reduction of adhesion strength of the coating to the substrate at heat treatment temperatures of 600 °C and 800 °C.
In the case of the heat treatment at 1000 °C, the recrystallization process was followed by the coarsening of the substrate grain.

In polycrystalline ZnO thin films obtained by sol-gel coating method, it is clear that the grain, grain boundary and ZnO layer-electrode impedances are present and the electrical properties of the film are determined in general by a series combination of such impedances.
The conductivity of these films can be attributed mainly to charge transfer through grain boundaries, crystal defects, and noncrystlline phase between ZnO crystals.
Since, excess ionized oxygen vacancies introduced by annealing treatment can provide a large number of electrons to fill the electronic states of the conduction band during the exciting process, and the electrons excited from the valence band can only fill the electronic states with higher energy.