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The measured smallest and largest particle sizes were 0.54 and 112.25 μm, respectively, and the values of average size (d50) were 7.73 and 3.31 μm for size distributions in volume and number fractions, respectively.
The distribution curve in number fraction showed one main mode with peak at about 4 μm and a secondary mode at around 0.6 μm (Fig. 1b).
Fig. 1 – Particle size distribution curves as a function of volume (a) and number (b) fractions of particles of milled powder.
The chemical etching highlighted the intermetallic matrix, and also revealed the grain boundaries in WC phase, showing that the grains of this phase varied between about 1 and 7 μm (Fig. 3b), which range was similar to the particle sizes determined by granulometer of the milled powder (Fig. 1).
These results indicated that there was no significant grain growth of WC particles during the sintering by SPS.

The results showed the presence of massive dendritic crystals with a clear separation of tin in the prepared sample on the one hand, and on the other hand, fine grains of homogeneously distributed tin resulted from the excellent cooling level of double casting, where the very fast cooling speed kept the distribution of homogeneous components in a molten state and there was no time For grain growth, this means that this method is feasible to produce an alloy (Cu - 9 Ni - 6 Sn)[21-31].
But after the solvation treatment, the dendritic structure is completely destroyed and replaced with the homogenous fine-grained structure, as shown in Fig.2, as there is no attempt to control the size, shape and distribution of crystalline grains in the homogenizing solution, although there are specific amounts of fine-grained in the two quaternary alloys, Therefore, we conclude that the structure is stable in structure after homogenization.
Taha “Studying the Microstructure of Al-Ti Alloy Prepared by Powder Metallurgy using Three Different Percentages of Ti”, Journal of Engineering, Number 6 Volume 26 June 2020, , Baghdad university, Iraq,journal homepage: www.joe.uobaghdad.edu.iq
Abood, “Improving the Physical and Mechanical Properties of Fireclay Refractory Bricks by Added Bauxite”, Journal of Engineering, Number 4 Volume 25 February 2019, Baghdad university, Iraq,journal homepage: www.joe.uobaghdad.edu.iq
Abdull-Razzak, “Effect of bentonite addition on some properties of porcelain”, Journal of Engineering, Number 1 Volume 25 February 2019, Baghdad university, Iraq,journal homepage: www.joe.uobaghdad.edu.iq [25] T.

After annealing at 800o C, the hydroxyapatite films showed a microstructure with crystalline nano-grains, whereas the Ag-doped hydroxyapatite films revealed the formation of crystallites embedded in the amorphous matrix.
The HAp film images (a,b) revealed that they were composed of a number of crystalline nano-grains, whereas the Ag-doped HAp films (c,d) showed the formation of crystallite embedded in the amorphous matrix due to the effects of Ag doping.
The HAp film was composed of a number of nano-grains, yet the Ag-doped HAp films revealed the formation of crystallite embedded in the amorphous matrix.

One of the effective ways to increase the strength of diamond retention in composites for various purposes is the metallization of diamond grains [1,5-7].
Diamond grain with mass ≈0.03 car was set so that its polished side snug against the pressed rod from the side of chromium.
Natural diamond raw material of group ХV «а-2» with a total mass of 1 carat was used in both types of ruling pencils, the grains of which were stacked in three layers with 16 pieces in each one.
There is a relatively high proportion of diamond grains of the working layer that prematurely have pulled out in the control pencil.
Agren, Sintering shrinkage of WC-Co materials with bimodal grain size distribution, Acta Materialia, 53 (2005) 1665–1671.

The β-TCP, SF and β-TCP/SF’s chemical functional groups and bonds were analyzed with Fourier transform infrared (FT-IR, Nicolet NEXUS 470) with the wave-number range of 4000 ~ 400 cm–1.
Third, the characteristic peaks of SF are moved to the large wave number.
(Fig. 3) Fig. 3 SEM photos of β-TCP/SF before soaking (a) and after soaking (b) According to Fig. 3, we can find that the surface of complex is scraggly and has different size grains of β-TCP; few fibers agglomerate structure constitutes by SF closely combine with grains of β-TCP, 3D pore structure.
However, 16 days later in SBF, the fibre agglomerates structure is disappeared, and the grains on the surface of β-TCP/SF are same sizes and uniform distribution; and the globular grains are made up of vermiform slender crystal; there also have a different size void between the globular grains.
It shows the globular grains are made up of bone-like apatite.

As solutions to these problems, previous studies have proposed a number of wood-processing methods that take advantages of the characteristics of wood biomass.
Bamboo culm consists of parenchyma cells and hard fibers [10], so it is considered that the large needle-shaped grains are part of the hard fibers, and the small round grains are part of a parenchyma cell.
A change in grain shape caused by heat treatment was not seen, but the color of the powder did change.
It is considered that the decomposition rate of cellulose in boiled powder was lower than that for steamed powdered because the amount of acid on the surfaces of boiled grains was lower than that for steamed grains, as shown in Fig. 5(b) (iv).
Acknowledgment This work was supported by JSPS KAKENHI Grant Number 24360309.

The grains on both sides of the fusion line had finished the recrystallization.
The isometric crystal in the base material had no obvious change, and grain size kept 45-55μm.
Besides, the precipitation of γ’ phase would also restrict the growing up of grain.
Especially after aging treatment a large number of rod-shaped sediments were found (Fig.12).
One of the reasons that the strength of welding seam was better than that of the material base was a large number of TiCN were precipitated.

In 5xxx alloys IGC is caused by the formation of b-Al5Mg3 precipitates along the grain boundaries.
After an extended thermal exposure in the range 70-200°C these b-Al5Mg3 particles tend to precipitate along the grain boundaries, which is detrimental with a view to IGC (e.g. [1-4]).
(a) BSI-etched, showing heavy grain boundary precipitation; (b) microstructure after NAMLT test, showing heavy corrosion attack by IGC.
Thermodynamical simulations of phase contents The alloy development is based on micro-chemistry simulations to detect potential alloys with subsequent experimental trials to characterize the final-gauge properties of a small number of suited alloys.
Since IGC requires a continuous layer of b-phase along the grain boundaries, a certain amount of b-phase below the values of current alloys was tolerated.

The average grain size of the CuAl0.9Fe0.1O2 compound prepared increased with increasing sintering temperature, whereas its mean pore size and porosity decreased with increasing sintering temperature.
It was found that, as the sintering temperature increased, the grain size of the samples also increased from 2.0 to 5.0 µm, and their porosity decreased.
The pores were mostly located at grain boundaries.
In general, for a given compound, electrical conductivity increases with increasing grain size and decreasing porosity.
The electronic contribution to thermal conductivity, Kel, was calculated using Wiedemann-Franz law, Kel = LσT, where L is Lorenz number, σ is electrical conductivity and T is the absolute temperature.

A great number of works are known, which are dedicated to finding out the relationship between the peculiarities of the laser shock-wave treatment technology and the structure and mechanical properties of implants [3, 4].
Despite a high interest in the practical use of titanium, there is only a limited number of investigations dedicated to the mechanisms of deformation under shock-wave treatment [5].
The formation of steps on the surface of spalling is connected with different orientations of grains.
In case of the crack propagation through separate disoriented grains, for which the soldered areas deviate significantly from the direction of the main crack, the dimple tears are formed, Fig. 3b.
As the spalling crack passes through the grain boundary, the crack splits into a number of separate microcracks, which propagate in parallel.