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Introduction The control of grain structure represents a fundamental aspect in developing the desired mechanical properties and formability characteristics in aluminium alloys.
Both dispersoid types typically exhibit sub-micrometer dimensions (100-300 nm) and develop at considerable number densities during homogenization, thereby providing effective anchoring points for grain boundaries and substantially retarding recrystallization processes during subsequent hot deformation.
The Smith–Zener pinning effect of dispersoids has been shown to refine the grain structure after hot rolling significantly.
Input was the equilibrated composition profiles of solute elements across the grain interiors of the α-Al matrix as calculated from DICTRA at t = 10 hrs.
These results underscore the critical role of dispersoids in retarding grain boundary mobility, thereby effectively suppressing recrystallization and controlling the grain structure during subsequent thermomechanical processing (Fig. 4c).

Its phase composition and microstructure were characterized by using XRD, SEM,and its high temperature anti-oxidation property were studied by isothermal oxidation tests.The results showed that the coating is composed of mainly α-SiC and β-SiC,the coating is uniform, compact, perfect grain growth, without crack, closely with the C/C materials,the thickness is about 600μm.
In the first stage, carbonaceous material on the surface of C/C composites reacted with siliceous gas of the furnace and formated SiC; in the second stage, a large number of SiC was synthesized in furnace when the temperature of furnace core reached the 2600 [12], at so Fig. 1 XRD patterns of SiC coating high temperature, the surface of synthesized solid-phase SiC which easily decomposed or evaporated and turned into vapour was called SiC reactivity gas, such as Si,Si2C,SiC2,SiC, the gas agglomerated, deposited and reacted in the pores structure inner ceramic coating formating SiC.
From Fig.2b, it can be seen that large SiC grains together with micro-crystals are both present on the coating surfaces, its morphologies mainly be composed of well-crystallized, hexagonal, dense SiC crystal, which is advantageous to improving the oxidation resistance of the coating.
The transition layer with a thickness of around 200μm is not very dense.This layer was formated by reating carbon residue with SiO gas and generated SiC, which keeped vitreous carbon structure with a large number of porous structure; reating substrat with SiO gas and generated SiC,which had same structure with the matrix, therefor there had a perfect transition gradient of phase structure from C to SiC and good associativity, the coating had good chemical compatibility with C/C composites,it will be avoid that the coating occur crack,even separate from substrat because expansion coefficient mismatch during high temperature environment.
In the first stage, resin of the coting was carbonized and formating high-carbon residue vitreous carbon at high temperature, at the same time gas SiO, Si, SiO2 , etc of SiC industrial synthesis furnace diffused into the porous structure of the coating and reacted with those vitreous carbon, petroleum coke, then formated SiC, which retained the structure of carbon network porous structure, this stage occurred in the early stage of synthesis SiC; the second stage was the key stage of obtaining excellent performance of high temperature anti-oxidation coating, to occurr in the later stage of synthesis silicon carbide, a large number of SiC synthesized in this furnace easily evaporated and turned into gas Si, Si2C, SiC2.

Carried on an observation to the variety that vegetation dam’s in front and back single grain sediment sport speed, and silted up appearance with the sediment in the dam to carry on analysis before the dam to the plant.
Introduction Plant "flexible dam" in the channel or canals, the main tank, and by certain plant spacing and line spacing, planting a certain number of sea buckthorn tree [1] Sea buckthorn is an Elaeagnaceae shrub, it has developed the spurious branches prone to deflection in the hydrodynamic effect, so called "flexible dam".It can slow down the rate of water flow, intercept flood backdrop of a large number of coarse sand, which is mainly of bed load sediment, sand fixation and restore the ecological role[2,3].
Model tree lined optimized water test water blocking the best of the 6 cm × 9cm × 9 ranks staggered arrangement shown in Figure 1, 6cm for the spacing in the rows, 9cm for spacing, 9 is the number of rows, 72cm dam planting a tree for 63 planting density of 248 / m2.
Table 1 Single grain damping extent in average sport velocity after planting table bottom slope Particle size(mm) flow(L/s) 5.09 9.08 13.08 1/150 4~5 100% 76.29% 76.76% 3~4 100% 79.03% 74.88% 2~3 100% 80.96% 76.30% 1~2 100% 81.77% 74.31% 1/100 4~5 29.55% 23.21% 19.88% 3~4 26.65% 22.86% 20.95% 2~3 26.86% 20.58% 21.04% 1~2 32.99% 17.29% 20.85% 1/50 4~5 8.05% 19.16% 18.75% 3~4 7.06% 19.58% 21.70% 2~3 7.69% 12.27% 20.87% 1~2 0.92% 11.68% 19.40% Longitudinal Analysis of Sediment Deposition The different flow of the bottom slope, sediment deposition thickness along the vertical increases gradually and forms a peak in front of the dam.

Figure 2 gives details of known cracking events in nickel-base alloy welds as number of failures vs. operating time.
Wrought materials have generally equiaxed shapes of grains.
Recent work has shown that the misorientation between the grains can vary significantly even along the wavy grain boundaries.
[4] INCONEL Alloy 600, Publication Number SMC-027, Special Metals Corporation, 2002 (Sept. 02)
[5] INCONEL Alloy 690, Publication Number SMC-079, Special Metals Corporation, 2002 (Sept. 02)

Table.2 Heat treatment process number Specific process 1 casting 2 850°C×2h Furnace cooling 3 850°C×2h Furnace cooling+880°C×30min oil cooling 4 850°C×2h Furnace cooling+880°C×30min water cooling Results and Analysis Mechanical properties of the test cast steel.
Table.3 The hardness values of the35CrMnSiMo cast steel number The hardness 1 160.3* 2 125.4* 3 38.6 4 49.6 Note: * data is HB, the other is HRC （HB），其余是HRC ( HB ), the other is HRC The specimen impact tests were performed in the automatic metal pendulum impact testing machine ZBS-300B, record the data as shown in table 4.
Table.4 The impact toughness values in different conditions number AK/J αK/J/cm2 1 32.25 40.33 2 47.90 59.88 3 32.75 40.18 4 31.04 39.04 Contrast analysis on the mechanical properties.
According to the relation of conversion between hardness HRC and hardness HB, ( HRC ) = HB /10-3, the hardness value of the number.1 is 13.0HRC, the hardness value of the number.2 is 9.5HRC.
Figure 3.a is a photomicrograph cast without any heat treatment before the cast metal containing large pores, the columnar dendrite grains, and these grains there is a serious segregation, these directly affect the various properties of the steel,by heat treatment can significantly improve this situation; Figure 3.b is an annealing photomicrograph can be seen, after 840 °C after the furnace cooled, the mechanical properties of its degree of thickness of the tissue of the large areas of the pearlite structure, pearlite type.

Meanwhile, with the development of computer simulation and virtual reality technology, a number of dynamic analysis software can be used for metal cutting process, such as LS-DINA, MSC.Dytran, Abaqus, Deform 3D, etc.
Brinksmeier, Aurich depicted the method of the single grain simulation in grinding process and the experimental verification.
Wang and Ye made use of Deform 3D to carry out the surface grinding simulation of single grain, which assumed the grain shape, and made the corresponding experiment [4].
The yield stress in this model is the function of plastic strain, strain rate and temperatures : (8) Where ; = Plastic Strain; = Strain Rate Parameter; = Reference Strain Rate; = Temperature; = Room Temperature; = Melt Temperature According to above formula, Hu Changming and He Hongliang carried out a large number of experiments to fit J-C constitutive model for 45# steel, which can be expressed as follows: (9) Where = and = The hardness of CBN is much higher than the machined materials.
The key problems of simulation are settings of the material constitutive model and contact algorithm parameters, which is need a large number of experiments to determine the relevant parameters.

Only a small proportion of the diamond grits can penetrate the flexible pad surface; most diamond grits are attached to the disk with no function, affecting the number of working diamonds, and the diamond disk life.
The PCD substrate is formed from inter-grown matrix microscopic diamond grains (e.g. 10 microns) with a volume-occupancy of over 95%.
Each diamond grain is strongly supported by merging with surrounding grains, so the global structure is virtually a continuous diamond mass.
In the Figure, the number of effective cutting tips of the PCDD was larger than that of the BDD, owing to the PCDD having identically shaped tips.
This implies that the PCDD has a much larger number of cutting tips that are sharing the dressing loading.

They created and investigated a number of coatings on low carbon steel using cladding of boron [1], the mixtures of titanium, carbon and molybdenum [2], iron and carbon [3], iron and boron [4], titanium, carbon and boron carbide [5], Ni-Cr-Si-Fe-B [6], etc.
As was noted above, a number of coatings of different composition are created on low carbon steel using non-vacuum electron beam cladding of powders.
Number 1 2 3 4 5 Energy, [kJ/cm2] 7.4 8.8 10.0 11.7 12.7 The structure of the coatings in the cross-section was studied using scanning electron microscopy (SEM) in a Carl Zeiss EVO 50 microscope.
The less TiC particles lie both inside austenite grains and on their boundaries.
The concentrations of chromium and titanium in the coatings: average concentration in the near-surface layer (a), in the austenite grains (b) and in eutectic (c).

Table 1 Simulating test cases Testing number A1 A2 C1 C2 C3 C4 Layers of geogrid 0 0 2 2 2 2 Differential settlement[mm] 0 30 0 20 30 50 The test simulates the capability of road top load by employing the method of plane loading test, in which the loading board is a 60cm×30cm×2.5 cm (length × width × thickness) steel boards, and the maximum loading capability is 126kN and the maximum stress is 0.7Mpa.
The grain composition and the physical-mechanical properties (Table 2) of the soil are tested according to the method in Test Methods of Soils for Highway Engineering JTG E40-200.
Table 2 Physical and mechanical indices of soil Gradation of grain Indexes of physical-mechanical property Grain size [mm] Percentage [%] Liquid limit [%] 27.68 >2 6.26 Plastic limit [%] 21.50 2~0.5 35.86 Cohesion [kpa] 13.00 0.5~0.25 18.92 Angle of friction [°] 31.00 0.25~0.074 17.18 Maximum dry density [g.cm-3] 2.048 ＜0.074 21.78 Optimum moisture content [%] 12.02 Table 3 Main mechanical indices of geogrid 　 Testing projects Testing value Standard deviation Coefficient of variation [%] Lengthwise Tensile strength [kN.m-1] 44.50 0.49 1.09 Maximum elongation percentage [ %] 23.86 0.66 2.77 2% Tensile strength [kN.m-1] 15.47 0.68 4.37 5% Tensile strength [kN.m-1] 24.76 0.59 2.40 Crosswise Tensile strength [kN.m-1] 39.01 1.17 3.00 Maximum elongation percentage [%] 10.05 0.67 6.71 2% Tensile strength [kN.m-1] 16.77 0.39 2.30 5% Tensile strength [kN.m-1] 30.60 0.75 2.47 Geogrid.
The test results show that under the same loads in the working condition A2 (the number of geogrid N=0, the differential settlement of embankment △S=30mm) the settlement of loading board is greatest but the vertical settlement deformation can be apparently reduced after the geogrid are set-in.
By comparing the working conditions of A2 and C3 (the number of geogrid N=2, the differential settlement of embankment △S=30mm), with the same △S initially, when the load is below 50.4kN whether there is a geogrid has little impact on settlement, but when the loads are 63kN, 75.6kN, 88.2kN, and 100.8kN the settlement in C3 reduces apparently which is amount to 86%, 74%, 64% and 52% of that in A2; hence, the geogrid has greater impact on decreasing vertical settlement in C3 than in A2.

Fig.2 Temperature curve of different samples at 1 200 oC Fig.3 The thermal insulation property of different temperature Fig.4 SEM morphology of sample surface Fig.5 SEM micrograph of fracture surface For the thermal barrier coating of nano-Al2O3 coated ZrO2/Y2O3 powder, in the nanostructure field of the unmelted nano-powder, a large number of coating grain boundary and tiny pores of nano size enhanced photon scattering effect and decreased the thermal conductivity of the coating.
Therefore, the number of grain boundary, pores and the internal layer structure of the coating increased with the coating thickness increasing, which improved the thermal insulation performance of the coating.
The former is composed of many nano composite particles, which have a large number of voids and interface.
Effect of thermal treatment on the grain growth of nanostructured YSZ thermal barrier coating prepared by air plasma spraying.