Search results

Because the stored grain insect action sound are to weak too be detected, and also affected by the environment noise, the effective extraction of insect action sound has become the key of the stored grain insect sound detection.
The design ideas of the sound insulation chamber The stored grain action sound is the sound generated when insects, which grow in the stored grain heap, feed stored grain or creep in stored grain.
The stored grain insect feeding or crawling sound is generally as a unit with a pulse.
Because the stored grain system contains both solid structure and gaps, the sound wave is the multi-mode wave and mainly propagates through the gap of grains[2].
Sound detection of stored-product insects that feed inside kernels of grain.

In these simulations, the triple points of grains were joined by straight segments.
The Read-Shockley expression in Eq 4 is used for the grain boundary energy [7].
The brass microstructure did not evolve significantly even after several hundred thousand iterations, while the Goss structure showed a significant growth in sub-grains after a similar number of iterations.
The same is true for a very large number of boundaries in the Goss oriented deformed crystal.
[7] G Abbruzzese, K Lücke, A theory of texture controlled grain growth – I.

refers to the total density of dislocations in coarse-grains and the nano-grain.
The back stress induced by dislocations accumulation can be simply expressed as (4) whereis number of dislocations that emit from the nano-crack tips.
As illustrated in Fig. 1, we only consider the number of dislocations emitted from the crack tip of NC copper when the angle is 70°.
can be get from (5) where is the maximum number of edge dislocations that can be emitted from the crack tip along one slip plane, it can be get from the Fig. 2.
The strength of the material decreases with increasing the grain size of the coarse grain.

While dressing the grain tips of the coarse grained grinding wheels are truncated by the diamond grains of the dressing cup wheel.
The results demonstrate that the new dressing method for single layered coarse grained diamond grinding wheels offers a number of advantages over the mechanical dressing technique [6].
Experimental results For the dressing experiments single-layered coarse grained diamond wheels with a grain size of dG = 181 and 301 µm, stochastic grain distribution and a grain concentration of C = 100% are investigated.
A number of experiments have been conducted to investigate the feasibility of the new dressing process to eliminate wheel waviness and obtain a sufficient run-out, as well as removing the highly protruding grain tips and obtain flattened grains with a uniform protrusion height.
Thus, the flattened grains´ topography and their average grain protrusion hk were derived.

THE INFLUENCE OF SECOND PARTICALS ON GRAIN BOUNDARY SLIDING Jianqiang ZHANG1, a, Jun ZHANG1, a, Guosen ZHU1, a, Yanjun Zheng2,b, Shaowei LI2,b, Fenghui WANG1, a 1Shougang Research Institute of Technology, Beijing, China 2China University of Petroleum (Beijing), China azjq0943@126.com, b476968282@qq.com Keywords: second phases; grain boundary; sliding; SCC crack Abstract.
The effect of second particles on the grain boundary deformation in 304 type austenitic stainless steel was studied.
It seems that the sensitized material decreased creep rate and needed more stress to generate deformation of grain boundary, suggesting Cr carbides decreased the grain boundary sliding.
However, if the grain boundaries are decorated by carbides, the ability of resistance to SCC crack propagation can be improved remarkably.
SCC is highly chemically specific in that certain alloys are likely to undergo SCC only when exposed to a small number of chemical environments.

Concentration Profiles For Grain Boundary Diffusion in B-regime With Regard To The Formation Of Atomic Complexes In Grain Boundary Vladimir Esina, Boris Boksteinb, Alexey Rodinc National University of Science and Technology “MISIS” (MISIS), Department of Physical chemistry, Leninsky pr., 4, 119049, Moscow, Russia avladimir.esin@misis.ru, bbokst@misis.ru, crodin@misis.ru Keywords: grain boundary diffusion, grain boundary segregation, atomic complexes in grain boundary, nonlinear concentration profiles Abstract.
Thermodynamics of the atomic complexes formation in a grain boundary (GB) is discussed applying to AB complex.
Introduction Commonly accepted model of grain boundary diffusion (GBD) was given by Fisher [1].
A large number of experiments affirm this conclusion [4,5]. 1.
Equilibrium and nonequilibrium segregation The equilibrium between GB and grain leads to the adsorption (segregation) isotherms of different types.

The number of forging passes was 10, leading to the total cumulative strain of 4.0.
A number of processing techniques allowing the plastic working up to very large strains at relatively low temperatures including severe deformation at room temperature have been developed and practically utilized.
The total number of forging passes was 10 that resulted in the total cumulative strain of 4.0.
The dotted lines in (c) outline roughly original grains.
Besides twin boundaries, a number of strain-induced (sub)boundaries developed in the initial grains.

Moreover, it appears that significant grain refinement was achieved after 2 complete revolutions and thereafter the microstructures do not really vary after additional numbers of turns.
The average grain size and the fraction of high-angle grain boundaries (HAGB) are plotted in Fig. 2 as a function of the number of HPT turns.
(d) (c) (b) (a) Fig.1: EBSD images of AlMgSi alloy after HPT deformation for (a) 1, (b) 2, (c) 4 and (d) 5 turns Fig.2: Average grain size and the fraction of HAGB versus number of turns.
The evolution of torsion texture versus number of turns can be interpreted with the aid of the key given Fig. 3 (f) which shows the positions of the texture components.
The microstructures after HPT revealed considerable grain refinement characterized by the formation of submicrometer grains of about 500 nm and a high fraction of high-angle grain boundaries. 3.

The average grain size after strain application was 0.5 µm.
As a result, 67µm equi-axial crystalline grains were obtained.
The current study result also supports the high grain-size dependency on yield stress that has been reported in crystalline grain refining methods [1-3].
At the same time, we have deduced that, although low-misorientation grain boundaries and high-misorientation grain boundaries are formed in parallel in uniaxial working, by making the working multi-axial, the intersection of the low-misorientation grain boundaries divide the inside of the original grains finely and uniformly, which consequently form a nearly equi-axial grain structure in high strain regions [1-3, 5].
Conclusions An increase in the number of strain paths is most effective for the easier evolution of ultrafine grains in high-strain working.

Shows the samples with different content of sintering adds Sample number Additive types and content Sample1 Sample2 Sample3 No additive 0.5wt% SiO2 0.5wt% SiO2 and 0.5wt%MgO Optical transmittance spectra.
The grain boundaries were clean, and the average grain size was about 30μm.
Sample number Additive types and content Sample4 Sample5 Sample6 0.3wt% MgO 0.5wt% MgO 1.0wt% MgO Action mechanism of MgO.
The redundant MgO has a pinning effect on the grain boundaries so as to decrease the grain size.
The grain size decreased with the increasing MgO.