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This is a complex, energy-intensive, multistage, chemical and power engineering process (CPEP), consisting of an interrelated set of endothermic processes of dissociation of carbonates contained in the grains of raw pellets and the simultaneous process of grains sintering.
Furthermore, the generation of an amorphous phase leads to a decrease in strength, while heterogeneous reactions form product crystals and a new inter-crystalline surface in individual grains, which leads to cracking and a decrease in the strength of individual grains.
The grains are sintered with each other independently of the processes inside the grains.
During decarbonization, the grains porosity e2 increases, and during sintering pore space and porosity decrease simultaneously.
Acknowledgment This research was funded by RFBR under the research project No 18-29-24094 and the framework of the state assignment, project number FSWF-2020-0019.

This indicates that inside a single grain seen from SEM micrograph, there exists a smaller crystallite [15].
It is clear that many particles form a structure like a number “eight”, showing a neck that connects two closest particles.
It has been known that the requirement for a microstructure to be stabilized is grain boundaries that remain attached to each other [16].
This is also the reason behind the similar grain size of each samples despite the difference in the sintering temperature.
Acknowledgments This work was financially supported by Universitas Indonesia under research grant “Hibah Publikasi Internasional Terindeks Tugas Akhir (Hibah PITTA B) 2019” with contract number NKB-0619/UN.R3.1/HKP.05.00/2019.

As the surfactant, Ce is easy to dissolved in internal grain, which caused by the distortion energy is much higher than dissolved in the grain boundary.
So, Ce is priority segregation at the grain boundaries, reduces the interfacial tension and energy, and decreases the driving force of grain growth, and hinders the movement of grain boundaries and inhibits the growth of grain.
First, Ce can make the grain refinement, the grain boundary increasing and increase the resistance of dislocation movement.
Then a number of interstitial atoms that pin dislocations are reduced, thus the tensile strength of steel are improved.
Finally, the appropriate amount of Ce that dissolved in the steel is often enriched in the grain boundary by diffusion mechanism, which reduces the inclusions segregating in the grain boundary, so it reinforces the grain boundary.

Because in the high concentration of carbon atmosphere, a large number of carbon atoms combined with Ti to form TiC, and reduced the formation of diamond.
We calculated the grain size by Eq.1.
In Fig.3 (1~5) the grain sizes of diamond (111) orientation were 40.2nm, 43.4nm, 49.5nm, 33.1nm, 40.5nm.
In Fig.3 (1~4) the grain sizes of diamond (220) orientation were 41.4nm, 32.8nm, 39.7nm, 29.4nm.
It could be seen with the temperature went up the diamond (220) orientation grain size had a decreasing trend.

In the fine-grain part it reaches the values of about 360 HV10, in the coarse-grain part of about 260 HV10.
Fig. 13 shows very fine-grain structure of the fine-grain part of HAZ formed of ferritic-carbidic mixture.
The fine-grain part of the heat affected zone is formed of very fine-grain probably tempered martensite with fine globulitic particles of carbides.
It changes from the fine-grain ferritic-pearlitic mixture with equiaxed grains to the Widmannstätten structure.
The given material is hard to weld, however, the examined weld contains a great number of defects.

Severe plastic deformation (SPD) has been known as a method for materials grain refining.
(12) when the number n increases infinitely, it results to and then .
After every pass through the ACAP's die, a significant strain can be imposed on materials that lead to intensive fragment process for grain refinement.
Specification of SPD as the grain refinement method is highlighted by high hydrostatic pressure created in plastic deformation zone, which prevents microfracture growth of materials during the plastic deformation process.
The number of rigid blocks is any integer, but when the number of rigid blocks increases infinitely the solution becomes more correct.

Conditions for cutting edge truncation Truer JIS B4131 SDC x 200 x N x 75 x B x 6A2 75 x 5 x 20 Truer speed SN 600 min–1 Tool rotational speed S 2000 min–1 Traverse rate F 1 mm/min Depth of cut 1 μm Lubricant Dry Number of traverses 2 per cut Table 2.
The grain shape was imprinted in the scratch marks.
Observations of single-grain wheel Single grain Center of wheel Microphotograph of wheel end face 3D image of truncated grain Truncated area L Single-grain wheel experiments.
After electroplating, only a single grain was left on the wheel end face; other grains had been removed prior to sticking to the wheel.
A single grain is attached to the wheel end face.

With sintering temperature increasing from 1120℃ to1150℃, the density of sintered honeycombs increasing, powder particles bind together and become grains.
Results show that wall thickness 0.13~0.18mm, cell number (1/in2) 350~385, clear cross section (%) 73~80, specific surface Sv(sq m/cu dm）2.68~2.85； specific heat capacity Cp(J/g.K) 0.50~0.56, heat conductivity κ(W/m.K) 11.2~12.5.
Table.2 Structure parameters of sintered metal honeycombs Material Cell Size （mm） Wall thickness （mm） Cell number （1/in2) Clear cross section （%） Specific surface （sq m/cu dm） 410L honeycombs 1~1.2 0.13~0.18 350~385 73~80 2.68~2.85 Ceramics honeycombs 1 0.2 400 67 2.4 Table 3 Physical characteristics of 410L and ceramic honeycombs Material Density （g/cm3） Spec. heat capacity（J/g.K.）
It is obvious that raw powder particles bind together to be grains sintering at 1150℃ (Fig.2d), and the density of sintered honeycombs is higher than sintering at 1120℃.
With sintering temperature increasing from 1120℃ to1150℃, the density of sintered honeycombs increasing, the porosity and specific surface reducing, when sintering at 1150℃, 30minite, grains bind together closely.

For example, loss separation may forecast the best grain size for high frequencies.
Illustration of the variation of energy in a grain, a consequence of the presence of domain walls.
Eq. (1) is valid for grain size identical to the the single domain particle size.
The classical expression can be considered as the lower limit of losses when the number of domain walls is infinite [6].
If the grain size is very small, the Hysteresis losses are dominant [23].

Results and discussion Fig. 1 shows SEM morphologies of samples irradiated by HIPIB with shot numbers from 1 to 10.
Fig. 2 shows the surface microhardness of samples irradiated by HIPIB as a function of shot number from 1 to 10 under a load of 0.25 N.
It is believed that the surface hardening of irradiated samples mainly results from the grain refinement, precipitation of b phase and the increase in dislocation density induced by HIPIB irradiation.
Fig. 2 Relationship of surface microhardness on the AZ31 magnesium alloys irradiated by HIPIB to shot numbers.
Grain refinement and precipitation of b phase caused by surface remelting and rapid cooling under HIPIB irradiation are responsible for the improved wear resistance.