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These alloys in the marine atmosphere, industrial atmosphere and seawater environments all can produce intergranular corrosion, mainly because of the grain boundary precipitates of CuAl2 or Mg2Al3 and thus formed Cu-depleted or Mg-depleted zone caused.
Relative research shows that in 3.5% NaCl solution, the potential of η phase is significantly lower than aluminum 7B04 alloy matrix, therefore η phase as the anode dissolute preferentially, forming selective anodic dissolution channels along the grain boundaries [7].
In this case, the dissolution rate of the crystal grain boundary and the dissolution rate of the main body is different, resulting in intergranular corrosion.
When the inter-granular corrosion develops to a certain extent, the volume of grain boundary corrosion product formed is greater than the volume of metal consumed to produce a wedge effect, and holds the upper metal that has not been corrodent causing minor, discontinuous small lobes or very fine corrosion on the metal surface, in the worst case, serious chunk of metal layered cocked, from the base metal, resulting in denudation corrosion (Fig.2).
And marine environments contain a large number of Cl-, when the aluminum alloy material is used in marine atmospheric which is such a severely corrosive environment, combined effects of stresses and Cl- that can make the mechanical properties tend to decrease, respectively, is much more seriously effective than a single factor, because marine atmospheric corrosion environment and stress can promote mutual synergies, and accelerate the destruction of the material.

Results The microscopic shape characteristics of the before-and after- broken particles of Liuweidihuang-raw material The microscopic shape characteristics of the specimens of Liuweidihuang-raw material is clearly viewed under a microscope,such as thread-shaped catheter of dogwood, oval starch grains of yam,orange calcium oxalate crystal druses(paeonol)in root bark of the peony tree.The the average size of processed super-micro-particle of liuweidihuang is 250±48nm.
Table 1 The microscopic shape characteristics of the before- and after-broken particles Microscopic characterization Coarse crushing powders Nanoparticles A: The diameter of Starch grains (long oval, spherical, umbilical-points short slit-shaped) is 2μm-10μm.
Complex particles are composed with 2-5 single grains. many none B: The diameter of oval starch grain is 30μm. scattered seldom C: The parenchyma cells in dogberry are taupe brown, wizened and pitting. some none D: The epidermis closest to the skin of dogberry is orange or brown. few none E: Catheter of dogberry and yam is reticulated and whorled. few none Fig. 1 The microscopic characteristics of coarse crushing powders of liuweidihuang Fig. 2 The microscopic characteristics of nanoparticles after superfine pulverizing Comparison of drying technology The results of three kinds of drying methods on Liu Wei Di Huang suspension are as follows.
On the sub axis, there are a number of rings-shaped grinding media, which can move freely.

Introduction Spark plasma sintering (SPS) has emerged as one of the most significant and effective sintering techniques in the last few decades, primarily because of its versatility to sinter a variety of materials to full density with retention of grain size at much lower homologous temperatures in a shorter duration compared to conventional processes [1-3].
SPS uses moderate uniaxial pressures and an on-off dc pulsing current to sinter powders [4].During this on-off dc pulsing, there are large numbers of proposed mechanisms to account for the enhanced sintering behavior.
The fine grains in the neck zones were considered to have formed first through a process of local melting, and then rapid solidification, which is exactly the procedure of the neck formation.
Sample 1 (Fig. 2a) have obvious seam marks in grain boundaries.
According to the literatures, CaF2 added in the ceramic sintering process, in favor of purifying grain boundaries, while promoting densification, optimizing comprehensive performance.

As was shown in [1], the developed new approach of the composite diamond materials (CDM) synthesis made it possible to combine in one technological cycle the production of a metallized coating on the diamond grains surface and sintering, which provided better preservation of the coating, increased the level of diamond retention and the composites operational properties.
First of all, it should be noted that light grains of tungsten carbide mechanically penetrated to the transition zone, penetrating into the chromium shell around the diamond, formed during the stage of pressing the batch into the briquette.
However, in Fig. 2a, it’s seen that the tungsten carbide grains do not touch the diamond surface.
The mechanical introduction of cobalt grains into the transition zone, as in the case of tungsten carbide, is not detected (at least in the analyzed section).
Despite a large number of publications on this subject, most issues remain open and require careful research.

It is important to minimize the number of intermediate annealings during drawing, since the hardening of the metal during the implementation of various technologies for the preparation of the workpiece will be different.
Wire drawing (Fig. 2) leads to a decrease in the transverse dimensions of the grains (fibers) of the aluminum solid solution and the grinding of particles of excess phases.
Redikul’tsev, Interrelation of Crystallographic Orientations of Grains in Aluminum Alloy AMg6 under Hot Deformation and Recrystallization, Metal Science and Heat Treatment. 56(11-12) (2015) 650-655
Langdon, Influence of grain size on the flow properties of an Al-Mg-Sc alloy over seven orders of magnitude of strain rate, Materials Science & Engineering.
Kaibyshev Effect of Grain Size on Cryogenic Mechanical Properties of an Al-Mg-Sc Alloy.

Finally, the samples were rapidly cooled by immersing them in water to halt the grain growth of the microstructure.
The higher hardness of sample SA, maximum at 161.4 ±2.4 HV, is due to the dislocation barrier along the grain boundaries spread out most areas in the samples.
As shown in Figure 5c3, the Ni-rich second phase is wrapped with Cu precipitate along grain boundaries.
Summary In commercial applications, it is crucial to reduce the copper proportion and increase the number of additional elements while maintaining hardness values.
The SEM micrograph provides a visual representation of the unique microstructure of Alloy B, which features a higher Ni-rich second phase precipitated and wrapped with the Cu phase along the grain boundary.

The number of neighbours of a node is called the coordination number.
In order to obtain the model parameters, the PAM program digitally images the thin sections and stores the results as binary arrays depicting grain + cements (solids) and pore spaces [7].
The coordination number, Z, is defined as the number of pores that are connected at a node or pore junction.
The coordination number is a measure of the average number of branches meeting at a point.
Property Sandstone Carbo-A Carbo-B Number of pores 6493.8 9891.6 34842.8 Number of throats 11024.8 17364 72878.6 Average Coordination Number 3.360232 3.499334 4.177106 Number of connections to inlet 115.6 54.8 116.2 Number of connections to outlet 113 59.2 96.2 Number of physically isolated elements 69 319 13 Number of triangular shaped elements 12583.4 11725.2 33095 Number of square shaped elements 4435.4 10311.4 50343 Number of circular shaped elements 501.8 5221 24285.4 Median throat length to radius ratio 7.2248 7.825432 7.555422 Average porosity 0.1879846 0.185026 0.3063856 Absolute permeability (mD) 482.367 8.091074 0.1603392 Absolute permeability (m2) 4.762E-13 7.99E-15 1.58E-16 Formation factor 49.6053 61.10224 17.73748 Figure 7 Comparison of Coordination Number Distribution.

The grain size, morphology and shape of the particles were characterized using FESEM and revealed rod-like structures.
Zinc oxide has been prepared by a number of methods such as hydrothermal method [15, 16], sol-gel [17-19], precipitation [18,19],solid–vapour phase thermal sublimation technique [9] and self-combustion [21,18] methods, producing various morphologies, sizes and characteristics.
The grain size, morphology and shape of the particles were characterized by using FESEM (SUPRA 55VP).

Every year a huge amount of plant refuse from production of grain, oil-bearing and other crops-remains, the bulk of which has a negative impact on land and water resources.
Thus, when producing one ton of grain, from 1.5 tons (barley) to 2.4 tons (corn) of straw is formed.
In recent years, the number of studies on various types of biochar used as soil modifiers and fertilizers, additional materials for composting and anaerobic fermentation, additives for recovery of contaminated soils, sorbents for removal of various organic and inorganic pollutants, etc. has been steadily increasing in the literature [7, 8].

Due to necessity of application very fine mesh with large number of elements, these solutions are computationally very costly.
Such approach allows comparison not only individual numbers but also the whole rheological curves identified for microstructure and SSRVE.
Non-uniform rational B-splines (NURBS) were chosen as grains representations.
However, RVE model has allowed to detect the localization of high longitudinal stresses at grains of perlite, as well as their very high localization near the axis of the rod.
The number of errors during the optimization was decreased below 2.5%.