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The increment of the annealing temperature results in the larger and denser grains.
The grain size of the Al-ZnO films that was measured by the Scherrer formula increased from almost 21 to 39 nm by the increment of the annealing temperature from 450 to 750 οC.
Additionally, as it has been reported earlier, the grain size increases by annealing temperature increment in ZnO films [15].
The resistivity of Al-ZnO films generally decreases by increasing the annealing temperature, as a result of decrement of the grain boundaries and crystal deficiencies of the film [15].
Acknowledgments The authors gratefully acknowledge the Faculty of Physics, Universiti Teknologi Malaysia through vote number of…….and research alliance frontier material.

Apart from conventional sintering process of aluminum metal matrix composite, the two-step sintering is simple and effective process used to attain grain growth and densification in each stage of the sintering cycle respectively [6-9].
The Reverse two-step sintering process was developed by Chen and Wang, which establishes an increase in the densification of the microstructure of the specimen while suppressing the grain growth of the specimen.
The fast cooling of the specimen allows the densification to occur in the microstructure while suppressing the grain growth of the specimen.
Usually, the specimen after compaction has a large number of porous and the density of the specimen is lesser, so to increase the density and decrease the porosity of the specimen sintering process is carried out.
In the Reverse two-step sintering, when the temperature is increased above the recrystallization temperature nucleation sites occur at different parts of the specimen for grain growth, so during the time t1 limited grain growth takes place (stage 1), and then the temperature is reduced from T1 to T2 and held for 180 minutes for densification process of the specimen (stage 2) and then the specimen is further cooled in furnace itself in order to provide coarse grain structure in the specimen.

The material’s strength is mainly determined by the volume fraction of hard phases, number and size of precipitates as well as grain size.
All steels consist of a ferritic matrix with martensite islands being mainly smaller than the ferrite grains.
The EBSD data confirm this finding by a doubled fraction of low-angle grain boundaries (LAGB) (Table 2).
In the HC steels, the IQ treatment does not lead to finer grain size but to the formation of lath-like bainite (mainly lower bainite) and to tempering of martensite.
Table 2: Metallographic data of the investigated steels (H: homogeneity, LAGB: low-angle grain boundaries 2-15°, HAGB: high-angle grain boundaries >15°).

There are two main morphologies appearing on the surface of pure zinc coating, one as flat and compact structure and the other with fine grain morphology.
Fig.5(d) shows the width and number of surface cracks of delta phase increasing with time, and local region has been exfoliation corrosion.
The Cl- ions prefer to attack the deformed zinc grains and produced pits.
The atomic number of Fe is more than double Al by the analysis of EDX, which is totally different from the atomic ratio of the inhibition layer Fe2Al5Znx[3,8,16].
However, these white grains were fixed composition of three-phase alloy by the proportions of Fe, Al, Zn.

With the improvement of IC integration, the number of metal interconnect layers in ULSI is increasing, feature size is shrinking.
Since the grain is consolidate in the abrasive block with certain structure and size.
Because of the grain is consolidate in the fixed abrasive polishing pad, the rigid of their positions are strong.
So that grain would not been pressed into the abrasive polishing pad[27].
And a large number of optical parts are non-planar.

Eigenacking degree of aggregates could be defined as the ratio of bulk density (ρb) other grain density (ρg) [13].
φ=1y1φ1+y2φ2-y2(1φ2-1)kdks (1) Table 1 Definition of Eq. 1 Terms y1, y2 Grain volume fractions of aggregates 1 and 2*: y1+y2 φ1, φ2 Eigenpacking degree of aggregates 1 and 2*. d1, d2 Characteristic diameter of aggregates 1 and 2*: dc=d1, max-d1, min1-0.3681+β+d1, min if β≤1.71740.632d2, max-d2, min(1+β)β+d2, min if β>1.7174 kd Factor that determines the diameter ratio effect: kd=d1-d2d1+d2 ks Statistical factor: ks=xx0k0 if xgrain size aggregate to larger grain size aggregate.
A total number of 10 RPC mixtures with various β values had been tested.
A total number of 10 mixtures with different β values had been mixed to investigate the effect of packing degree on the compressive strength of RPC mixtures.
Linear packing density model of grain mixtures.

Experimental Procedure and the Obtained Results After completing the heat treatment, a number of eight hardness measurements were performed on each sample, the average values ​​being: 147.9 HV0.5 (for C800 / R250), 128 HV0.5 (for C800 / R400), respectively 133.8HV0. 5 (for C800 / R600).
The microscope images (a,c,e) of the structures resulted after the thermic treatments and the SEM images of the cavitated surfaces after 165 minutes of exposure Findings: v At C800 / R250 samples, the application of the heat treatment of tempering to 250 ºC led to the precipitation from the supersaturated β phase of some α phase particles, with acicular shape, both inside the grains and on the boundaries between the grains (fig.3 a) .
As a result, the internal tensions are reduced, and the pinches appeared after the cavitation attack are somewhat stronger in the area of ​​the boundaries between the grains (fig. 3 b).
These structural changes are responsible for the increase in the number of caverns that affect the surface of the tested material to the erosion of cavitation (fig.3 d).
v At C800 / R600 samples, the tempering treatment at 600 ºC leads to an increase in the solubility of the α phase in the β phase which causes a slight decrease in the amount of α phase crystals and to a more intense coalescence of small, acicular, α crystals with formation mainly of larger, polygonal grains (fig. 3 e).

While the grain structure was not visible, a significant number of cracks were seen in both the cross-sectional (Figure 4a) and longitudinal (Figure 4b) directions of the parts as built.
Future work will include the confimration of the produced model using optimial process parameters, and an examination of the use of grain refiners which may allow a reduction in the hot cracking behaviour seen [8].
Acknowledgements This publication has emanated from research supported by the European Union’s Horizon 2020 Research and Innovation Program under grant agreement No. 862100, the Irish Research Council under Grant Number NF/2019/15931397, and Science Foundation Ireland (SFI) under Grant Number 16/RC/3872 and is co-funded under the European Regional Development Fund and by I-Form industry partners.
Easton, Grain Refinement of Alloys in Fusion-Based Additive Manufacturing Processes, Metall.
Qiu, Complete columnar-to-equiaxed transition and significant grain refinement in an aluminium alloy by adding Nb particles through laser powder bed fusion, Addit.

The results obtained show that the anatase to rutile transformation is started at about 750oC and the best size of produced powder grain is 20-25 nm.
In this method, there are more research possibilities with less cost because of the small number of the process steps and the low cost of the reactants.
Figure 7: Effect of calcination temperature on grain size of TiO2.

Hosford and Cadell refer to this roughening as measureable on the scale of grain size and occurring due to the orientation of neighboring grains on the surface and the movement of the grains relative to the surface during deformation [16].
A grain that deforms under compression in polycrystalline metal follows the slip systems.
It was found that the roughening tendency increases with a decreased number of slip systems, since the grains are restricted from being able to move in the direction of the macroscopic deformation.
Fig. 6 is the micrograph of the unformed AA3003-O shows and a mean grain size of 25 μm.
Not all the grains are equiaxial, some of the grains are elongated in the rolling direction.