Search results

N is the total number of slip systems.
The hardening is contributed by dislocations at both global and local slip systems levels within a grain.
Lin, et al, Three-dimensional virtual grain structure generation with grain size control, Mech.

The microstructure of obtained as-sinters (Fig.6-7) consist of mostly regular aluminum grains with dissolved copper in it and precipitations corresponding to the Al-Cu phase diagram.
On grain boundaries the pores, formed by incomplete consolidation of powders during compaction and sintering, are visible.
During slow cooling of aluminum alloy contains 4% of copper from α single-phase solution area to room temperature the large precipitations of ө phase forms on the grain boundaries of α solution.
The financial support of the State Committee for Scientific Research of Poland under the grant number 11.11.180.653 is kindly acknowledged.

After compaction and thermomechanical processing, the alloy is recrystallised to generate a coarse microstructure showing high grain aspect ratio to avoid as much as possible that the creep resistance be impaired by grain boundary sliding or the formation of grain boundary creep pores.
Therefore, an estimate of εc can be obtained directly from only the measurement of height h of a larger number of trajectories.

While for pH = 9, the platelet-like grains accumulate with each other to form the symmetrical hexagram-like LFP, with the size of about 25 µm (Fig. 1c, 1d).
The platelet-like structure transforms to porous spindle one with a large number of holes on the surface of LFP sample, as shown in Fig. 2a and Fig. 2b.
When the reaction condition is pH = 9 for 24 h (Fig. 2c, 2d), the LFP sample shows the corn cob-like microstructure with the average length of 3 µm for each grain.
The SEM studies indicate that pH condition and reaction time remarkably influence both the morphologies and grain size of LFP samples.

Over the past decades, a large number of plasticizing additives have been marketed, which have been fundamentally different in chemical composition and have different plasticizing effects.
It can be new (only crushed to the desired grain size) or recycled (reuse of originally new SiC or use of SiC from waste processes such as filter dust or debris from sample crushing) [10, 11].
It is a suspension made from crystalline grains containing nanoparticles, the so-called “seeding technology”.
Ribakov at al.: Using Granite Siftings for Producing Vibro-Pressed Fine-Grained Concrete.

Matsuda et al. [6] have shown that grain boundary diffusion of oxygen dominates the initial oxide growth process for Zirconium alloys.
Many large grains that is larger than 10 um in diameter and obvious cracks on surface can be seen by Laser Scanning Confocal Microscope (LSCM).
The transition area is able to tolerate a large number of sub-stoichiometry oxide phase and disorders through a second-order mechanism.
Furthermore, the crystal grains gradually grow larger because of the high temperature.

.%) Alloy number Zn Mg Cu Zr Fe Si LFS alloy 7.46 1.69 1.64 0.11 <0.01 <0.01 MFS alloy 7.46 1.69 1.67 0.11 0.03 0.02 HFS alloy 7.46 1.69 1.67 0.11 0.08 0.06 Results and Discussion Microstructure analysis for as-cast and as-homogenized alloys Fig. 1(a-c) shows the OM microstructure of the three alloys.
It can be easily observed from the OM images that apparent eutectic structure with net-like characteristics exists on grain boundary while the dendritic structure of them is similar.
From Fig. 4(a-c) we can see that abundant second phases with small size and relatively coarsen phases exist on grain boundary.
Some of them distribute in the matrix while the others lie on grain boundary.

In order to determine the quality of LSW a number of welding criteria has been proposed in the literature.
In the outer boundary areas a coarse-grained microstructure was observed whereas the inner areas show a very fine grain size.
Furthermore, an alignment of the grain orientation alongside the LSW was observed.

Technical requirements to be used as interconnect in SOFC should fulfil a number of specific requirements, i.e. a high oxidation resistance, a high electrical conductivity of the surface oxide scales, gas tightness, and a coefficient of thermal expansion matched to the electrolyte and the electrodes [1,2].
The surfaces of Fe80Cr20-53.33 and 38.51 nm were covered with compact oxide scale consisting of fine grain scales (Fig. 4a and b).
For the as commercial ferritic steels show coarser grain scales with the big nodules and spallation across the surface of specimen (Fig. 4d and f), but for the implanted specimen, it show better in finer nodule.
The scale on the surface specimen Fe80Cr20-53.33 nm indicated fine grained and discontinuous (Fig.5a).

Mainly because the sand ratio increases to a certain extent, proppant grain distribution is dense, the reunion phenomenon occurred in a fracturing fluid,and fracturing fluid viscosity makes the dense sand particles group act like a big particles, equivalent to greatly increase the particle diameter, causing particle settling velocity increase.This phenomenon is also referred to as "particle reunion" effect. 3.4 correlations for critical sedimentation velocity and particle settling velocity Through the analysis of the above experimental results, considering the influences of sand ratio, temperature and foam quality on proppant settling velocity and critical settling velocity of fracturing fluid, the type(1) and (2) are fitting results to show correlations form calculated the particle settling velocity ut and critical settling velocity Vcr of fracturing fluid, the average error are 12.32% and 13.5% respectively:
The proppant grain density is about 1700 kg·m-3. the type scope of application is: 0≤CS≤10%, 10%≤Г≤85%, 40℃≤T≤80℃, P=10MPa
Conclusion 1)The proppant transport experimental results show that with increase of the temperature, the proppant grain in GRF-CO2 foam fracturing fluid sedimentation rate increases,at the same time, the fracturing fluid critical settling velocity increase, showing the proppant transport performance degradation. 2)Under the condition of foaming, with increase of the foam quality, proppant particle settling velocity reduces, fracturing fluid critical settling velocity reduces, proppant transport performance increases;The change law under not foaming condition is just the opposite.
:“Thermophysical Properties of Fluid Systems” in MIST Chemistry WebBook, NIST Standard Reference DataBase Number 69, Eds.