scholarly journals Внутреннее трение на границах зерен, содержащих протяженные поры

2019 ◽  
Vol 45 (3) ◽  
pp. 23
Author(s):  
В.Г. Кульков ◽  
А.А. Сыщиков
Keyword(s):  
Shear Stress ◽  
Internal Friction ◽  
Grain Boundary ◽  
Temperature Dependence ◽  
Variable Shear ◽  
Scattered Energy ◽  
Cylindrical Pores ◽  
Mutual Displacement

AbstractA model of internal friction at a grain boundary containing equidistant parallel cylindrical pores is presented. Variable shear stress induces a mutual displacement of the interfacial regions matched at the segments between pores depending on their position. The values of scattered energy at each segment and total internal friction are determined. The temperature dependence of the internal friction has a form of a wide peak.

Observation of Stress-Driven Migration of Specific Planar Grain Boundaries in Al Bicrystals

2012 ◽  
Vol 706-709 ◽  
pp. 2886-2891 ◽  
Author(s):  
Dmitri A. Molodov ◽  
Tatiana Gorkaya ◽  
Günter Gottstein
Keyword(s):  
Shear Stress ◽  
Grain Boundary ◽  
Temperature Dependence ◽  
Boundary Migration ◽  
Activation Parameters ◽  
Tilt Boundary ◽  
Grain Boundary Migration ◽  
High Angle ◽  
Tilt Boundaries ◽  
Shear Coupling

Stress induced grain boundary migration was experimentally investigated in aluminum bicrystals. Migration of planar symmetrical <100> and <111> tilt boundaries under a shear stress was observed to be accompanied by a lateral translation of the adjacent grains. This coupling proved to be the typical migration mode for all investigated boundaries, no matter whether low-or high angle, low Σ CSL coincidence or non-coincidence boundary. The migration-shear coupling was also observed for asymmetrical tilt boundaries. Measurements of the temperature dependence of coupled boundary migration revealed that there is a specific misorientation dependence of the migration activation parameters. Contrary to expectations, a high angle Σ7 tilt boundary moved under an applied stress, but produced practically no shear during its migration.

INTERNAL FRICTION PEAKS CONNECTED WITH GRAIN BOUNDARY SLIDING IN Al

1983 ◽  
Vol 44 (C9) ◽  
pp. C9-759-C9-764
Author(s):  
E. Bonetti ◽  
A. Cavallini ◽  
E. Evangelista ◽  
P. Gondi
Keyword(s):  
Internal Friction ◽  
Grain Boundary ◽  
Grain Boundary Sliding ◽  
Boundary Sliding

Mechanical Spectroscopy Study on the Light Soaking Effect on Hydrogenated Amorphous Silicon

2012 ◽  
Vol 184 ◽  
pp. 416-421 ◽  
Author(s):  
H. Mizubayashi ◽  
I. Sakata ◽  
H. Tanimoto
Keyword(s):  
Internal Friction ◽  
Temperature Dependence ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Wide Distribution ◽  
Activation Energies ◽  
Mechanical Spectroscopy ◽  
Induced Changes ◽  
Mild Temperature ◽  
Hydrogenated Amorphous

For hydrogenated amorphous silicon (a-Si:H) films deposited at temperatures between 423 K and 623 K (a-Si:H423Kand so on), the light-induced changes in the internal friction between 80 K and 400 K were studied. The internal friction is associated with H2motion in microvoid networks, and shows the mild temperature dependence between about 80 K and 300 K (Q-180-300K) and the almost linear increase above 300 K (Q-1>300K). BothQ-180-300KandQ-1>300Kdecrease with increasing the deposition temperature, and show the mild temperature dependence ina-Si:H623K. The white light soaking with 100 mW/cm2(WLS100and so on) below 300 K caused a change inQ-180-300Kand no changes inQ-1>300K, respectively, and the light-induced changes inQ-180-300Krecovered after annealing at 423 K. The wide distribution of activation energies for H2motions between microvoids indicate that most of neighboring microvoids are connected through windows, i.e., the microvoid networks are existing ina-Si:H, and the spatially loose or solid structures are responsible for the low or high activation energies for the H2motion between microvoids, respectively. Furthermore, the light-induced hydrogen evolution (LIHE) was observed for WLS200to WLS400in a vacuum between 400 and 500 K, resulting in the disappearance of the internal friction due to the H2motion in the microvoid network.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

Temperature dependence of fractal dimension of grain boundary region in SnO2 based ceramics

2006 ◽  
Vol 41 (19) ◽  
pp. 6193-6197 ◽  
Author(s):  
Goran Branković ◽  
Zorica Branković ◽  
Daniela Russo Leite ◽  
José Arana Varela
Keyword(s):  
Fractal Dimension ◽  
Grain Boundary ◽  
Temperature Dependence ◽  
Boundary Region
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