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Firstly, in Fig.3 (a), a number of small crushed grains and/or sub-grains can be found in the Surface area, which makes the grain boundary present in a disorder distribution manner and hard to be identified unambiguously.
Besides that, some abnormal grains, which are surrounded by the refined and recrystallized grains, are also present either in the Surface or in the Center region.
And, the recrystallized grain size seems to become larger from the Surface to the Center area gradually, as well as the abnormal grain.
Moreover, in conjunction with the externally applied load, it makes a higher shear stress concentration at the grain boundaries rather than in the grain interiors.
Acknowledgements This research was supported by the National Key R&D Program of China, and the grant numbers are 2020YFF0218202.

Higher thickness films could be obtained by repeating the sequence of dipping, pulling and drying, until a desired number of times.
These patterns indicated that the film thickness had a remarkable influence on grain structure in ATO thin films.
It was due to that higher temperature would be propitious to grain growth.
to the range 523~773K, the grain growth became better, which resulted in the increase of the carrier mobility.
Antimony doping of tin oxide produced a number of effects: it accelerated the gelation, reduced the particle size and the degree of crystallinity of the gel, and decreased the resistance of the films.

A number of relatively simple, low-cost methods have been used to fabricate solar cells with efficiencies in the range of 10-16%.
The grain size of the film was also calculated using Sherrer's formula [3].
Grain size and surface morphology were revealed in accordance to scanning electron microscope (SEM).
The band tail (E0) at room temperature of the film relates with the grain size and can be calculated using the expression E0 = 21.18 + (121.84/R) where R is the grain size in µm [4].
The low sheet resistance is probably due to the large grain size leading to low scattering at the grain boundary which is good agreement with those reported elsewhere [5].

From each pieces, one specimen for obtained for each properties considered: - Density (ρ) - Strength in compression parallel to the grain (fc0), specimen exemplified in Fig. 1
- Strength in compression perpendicular to the grain (fc90) - Strength in tension parallel to the grain (ft0) - Shear strength parallel to the grain (fv0) - Longitudinal modulus of rupture in static bending (fm) - Longitudinal modulus of elasticity in compression parallel to the grain (Ec0) - Longitudinal modulus of elasticity in tension parallel to the grain (Et0) - Longitudinal modulus of elasticity in static bending (Em) - Modulus of elasticity in compression perpendicular to the grain (Ec90) Tests were carried out obeying recommendations of ABNT NBR 7190: 1997 [7].
Fig. 3 Specimen to compression parallel to the grain test Results and Discussions Table 1 and Table 2 shows mean values ​​(Xm), standard deviations (Sd) and coefficients of variance (CV) referred to properties considered of Dipteryx odorata.
Number of specimens, for each properties, is equal 12.
Dipteryx odorata (Aublet) Willd presentes properties in compression parallel to the grain load superior relative to others Brazilian native wood species, for example, Schizolobium amazonicum Herb. [9, 10].

However, solidification cracking in the weld metal has been observed in a number of cases after the initial deposit of Alloy 52 filler metal on the 316L substrate.
The length and number of cracks were measured and analyzed after the tests for each specimen, accordingly.
Table 2 exhibits the total crack length and number, and the average crack length with different delay times in the spot Varestraint tests of the weld metal specimens.
Obviously, most of the solidification cracks formed perpendicular to the tensile direction and propagated along the solidification grain or subgrain boundaries.
The total crack number was decreased but the total and average crack lengths were increased as the delay time increased.

The cement paste is modeled as a unit cell, which consists of three parts: dehydrated cement grain, gel, and capillary pore.
Garboczi and Berryman [1] developed new D-EMT considering the number of particles of a certain type and its overlaps.
Based on experimental regression of hydration degree of cement paste, Hua et al. models the autogenous shrinkage of cement paste at scale of hydration grains [4].
The macroscopic bulk modulus of cement paste is modeled by assuming that each cement grain is spherical, and the gel is assumed to coat and cover all cement grain surfaces.
Modelling at scale of hydration grains, Cem.

In all alloys, equiaxial beta grains were observed by optical microscope.
Introduction Although titanium is considered to be a ubiquitous element because it has the 9th-highest Clarke number of all elements [1, 2], it is actually classified as a rare metal because the current refinement process for the metal has a higher cost and consumes more energy than the processes used to refine iron and aluminum [3].
Manganese and iron are also considered to be ubiquitous elements, with the 11th-and 4th-highest and Clarke numbers, respectively, of all elements [1, 2].
All alloys contained only equiaxial grain structures and only the beta phase, except for the Ti-10Mn alloy.
In all alloys, equiaxial beta grains were observed by optical microscope.

With prior T4 heat treatment, the grain size of AZ31B Mg alloy increased from 6 µm to 17 µm.
Dynamically recrystallized grains were noted in the SZ for both specimens.
Wrought Mg alloy usually contains a considerable number of twin boundaries.
The number of twin boundaries for FSWed AZ31B-T4 specimens in the TMAZ appears to be smaller than that for H24 counterpart.
The number of twin boundaries for FSWed AZ31B-T4 specimens in the TMAZ appears to be smaller than that for AZ31B-H24 counterpart.

For its light quality, good thermal conductivity, and excellent electricity shielding performance, Magnesium alloy has been used in industry, agricultural and so on, for rare earth elements can improve the mechanical performance of magnesium alloy, the study of powder metallurgy is influence by rare earth magnesium is few at present. so, in this paper, by mixing powder metallurgy method the Y89 element was added in Mg17Al12 magnesium alloy, the influence of Y89 on microstructure, hardness and compression performance of Mg17Al12 magnesium alloy was studied, The experimental results show that when amount of Y89’s addition, the mechanical performance is more then and when is 1.22%, its mechanical performance is best, hardness is 66.7 HV, compressive strength is 113.6 MPa,increased respectively by 19.7% and 29.3% compared the Mg17Al12 magnesium alloy substrate, and the grain refinement effect of Mg17Al12 magnesium alloy is the best at this time.
The reason is the temperature increase, the atom move intensify, through surface shift and volume move, more atom insert the surface of the particle, and form the stick surface, the surface increase and form the agglomerated neck, with the neck increase, the connected hole which the particle form contract into close hole, and then turn into circle hole, all the same, the number of hole volume decrease, the distance of particle turn short, the density of the sample raise.
Fig. 5 Relation of compressive strength of MG17AL12 for the different content Y89 The experiment show the change relation of compressive strength and the grain size as follows: the bigger the grain size, the smaller the compressive strength of magnesium alloy; the smaller the grain size, the greater the compressive strength of magnesium alloy.
（1） Conclusions (1)Y89 act as grain refining for the magnesium alloy, and when the content of Y89 is 1.2%, the microstructure of MG17AL12 best

Dargusch2,d 1School of Metallurgy & Resources, Anhui University of Technology, Maanshan, 243002, China 2CAST CRC, School of Mechanical & Mining Engineering, The University of Queensland, Brisbane, 4072 Australia awhich@ahut.edu.cn, byejinlijie@163.com, cgui.wang@uq.edu.au, dm.dargusch@uq.edu.au Keywords: Pulsed current, steel, grain refinement.
There have been a number of studies on the effect of an electric current on the solidification and crystal growth of low melting point metals and alloys i.e. bismuth, cadmium, zinc, bismuth-tin alloys, aluminum and it’s alloys, lead-tin alloys etc [4-6].
It has been reported that the pulsed electric treatment can refine the solidified structure of a number of aluminium alloys, Pb-Sn alloys, and stainless steel under certain conditions because of the interaction between molten metal and the electromagnetic field [4-7].
Higher voltages (0-8V) produced greater grain refinement.