scholarly journals Anisotropy of the Kinetic Friction on a Single Crystal of Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 661-668 ◽  
Author(s):  
Katutosi Tusima
Keyword(s):  
Friction Coefficient ◽  
Slip System ◽  
Single Crystal ◽  
Tungsten Carbide ◽  
Basal Plane ◽  
Kinetic Friction ◽  
Track Width ◽  
Maximum Friction ◽  
Temperature Range

Abstract Measurements were made of the kinetic friction which occurs when a tungsten carbide ball slides in various directions on the surface of a single crystal of ice, the track width produced on the surface was also measured. Anisotropies were detected in both the friction coefficient and the track width. The track width φ was at a maximum when the ball was slid normal to the basal plane and a minimum when it was moving parallel to (0001) in the temperature range —5 to —30°C. Although the friction coefficient was at a minimum when slid normal to (0001) and maximum in parallel to (0001) at temperatures of —19°C and below, this relation was found to be reversed at temperatures of —10°C and above. Anisotropy in track width can be explained in terms of the amount by which a slip system contributes to deformation in a specimen. However, our understanding of frictional anisotropy calls for knowledge of the ploughing strength p defined by the adhesion theory of friction. It was found that p reached a maximum in parallel to (0001) and a minimum normal to (0001) and that the frictional anisotropy on (0001) was influenced by the value . A remarkable frictional anisotropy was also observed on the surface inclined to the basal plane at 30°; the maximum friction coefficient was twice the minimum, whereas the maximum track width was only 1.3 times the minimum.

scholarly journals Anisotropy of the Kinetic Friction on a Single Crystal of Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 661-668
Author(s):  
Katutosi Tusima
Keyword(s):  
Friction Coefficient ◽  
Slip System ◽  
Single Crystal ◽  
Tungsten Carbide ◽  
Basal Plane ◽  
Kinetic Friction ◽  
Track Width ◽  
Maximum Friction ◽  
Temperature Range

AbstractMeasurements were made of the kinetic friction which occurs when a tungsten carbide ball slides in various directions on the surface of a single crystal of ice, the track width produced on the surface was also measured. Anisotropies were detected in both the friction coefficient and the track width. The track width φ was at a maximum when the ball was slid normal to the basal plane and a minimum when it was moving parallel to (0001) in the temperature range —5 to —30°C. Although the friction coefficient was at a minimum when slid normal to (0001) and maximum in parallel to (0001) at temperatures of —19°C and below, this relation was found to be reversed at temperatures of —10°C and above. Anisotropy in track width can be explained in terms of the amount by which a slip system contributes to deformation in a specimen. However, our understanding of frictional anisotropy calls for knowledge of the ploughing strength p defined by the adhesion theory of friction. It was found that p reached a maximum in parallel to (0001) and a minimum normal to (0001) and that the frictional anisotropy on (0001) was influenced by the value . A remarkable frictional anisotropy was also observed on the surface inclined to the basal plane at 30°; the maximum friction coefficient was twice the minimum, whereas the maximum track width was only 1.3 times the minimum.

Kink and Crack Interfaces in Deformed 6H-SiC Single Crystals

1994 ◽  
Vol 357 ◽  
Author(s):  
X. J. Ning ◽  
P. Pirouz
Keyword(s):  
Low Temperature ◽  
Slip System ◽  
Single Crystal ◽  
Single Crystals ◽  
Basal Plane ◽  
Prism Plane ◽  
Secondary Slip ◽  
Micro Cracks ◽  
Indentation Tests ◽  
Temperature Deformations

AbstractWhen a 6H-SiC single crystal is deformed under indentation or uniaxial compression in orientations not favorable for the activation of the 1/3[1120](0001) easy glide system, the secondary slip system is activated. Additionally, for low- temperature deformations, “kinks” and/or micro-cracks form in the crystal. In this paper, experimental results on relatively lowtemperature compression and indentation tests of single crystal 6H-SiC, and the microstructure of the deformed crystals, are presented. Based on the results, the secondary slip system in 6HSiC has been determined to be 1/3[1120](1100), which may actually be a combination of alternate glide of 1/3[1120] dislocations on the (1102) and (1102) planes. Further, dislocation mechanisms for the nucleation of prism-plane and basal-plane cracks, and for the process of kinking, in deformed 6H-SiC are proposed.

Thermal conductivity of the single-crystal monoisotopic 29Si in the temperature range 2.4–410 K

2013 ◽  
Vol 55 (1) ◽  
pp. 235-239 ◽  
Author(s):  
A. V. Inyushkin ◽  
A. N. Taldenkov ◽  
A. V. Gusev ◽  
A. M. Gibin ◽  
V. A. Gavva ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
Temperature Range

Numerical Investigation of the Influence of Friction Coefficient on Brake Groan

2010 ◽  
Vol 44-47 ◽  
pp. 1923-1927 ◽  
Author(s):  
Xian Jie Meng
Keyword(s):  
Nonlinear Dynamics ◽  
Friction Coefficient ◽  
Degrees Of Freedom ◽  
Equilibrium Points ◽  
Static Friction ◽  
Kinetic Friction ◽  
Dynamics Model ◽  
Excited Vibration ◽  
Nonlinear Dynamics Model ◽  
The Stability

A two degrees of freedom nonlinear dynamics model of self-excited vibration induced by dry-friction of brake disk and pads is built firstly, the stability of vibration system at the equilibrium points is analyzed using the nonlinear dynamics theory. Finally the numerical method is taken to study the impacts of friction coefficient on brake groan. The calculation result shows that with the increase of kinetic friction coefficient /or the decrease of difference value between static friction coefficient and kinetic friction coefficient can prevent or restrain self-excited vibration from happening.

scholarly journals Магнитная анизотропия игольчатых монокристаллических включений MnSb в матрице InSb

2021 ◽  
Vol 47 (10) ◽  
pp. 46
Author(s):  
А.И. Дмитриев ◽  
А.В. Кочура ◽  
С.Ф. Маренкин ◽  
E. Lahderanta ◽  
А.П. Кузьменко ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Power Law ◽  
Anisotropy Constant ◽  
Temperature Range

The magnetic anisotropy of needle-like single-crystal MnSb inclusions in the InSb matrix was determined and studied in the temperature range 5 – 350 K. In granular InSb-MnSb samples a power-law dependence of the anisotropy constant K(T) on the saturation magnetization MS(T) is observed in the temperature range 5 – 350 K with an exponent n = 3.2 ± 0.4 in accordance with the theories developed by Akulov, Zener, and Callens.

scholarly journals Friction surface modifiers of carbon-containing material for high-temperature operation

2021 ◽  
Vol 2124 (1) ◽  
pp. 012013
Author(s):  
M N Roshchin
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Friction Coefficient ◽  
Friction Surface ◽  
Atmospheric Conditions ◽  
Temperature Range ◽  
Tribological Tests ◽  
Surface Modifiers ◽  
Antifriction Properties ◽  
High Temperature Operation

Abstract The results of high-temperature tribological tests of carbon-containing material in friction on heat-resistant stainless steel 40X13 in the temperature range from 20 to 700 °C under atmospheric conditions are presented. Friction surface modifiers “Argolon-2D” material improve antifriction properties and decrease friction coefficient value. Friction coefficient when using Ni-Se-PTFE modifier at load of 0.67 MPa and speed of 0.16 m/s is less by 5% than at speed of 0.05 m/s, and at speed of 0.25 m/s friction coefficient is less by 13% than at speed of 0.05 m/s. At 500 °C and a load of 0.67 MPa the friction coefficient when using Ni-Se-PTFE modifier is 30% higher than when using InSb-PTFE modifier, and the friction coefficient when using CuO-PTFE modifier is 1.2 times higher than when using InSb-PTFE modifier.

scholarly journals Heat capacity of lithium tungstate single crystal by DSC calorimetry data in the temperature range of 319-997 K

2021 ◽  
Vol 2057 (1) ◽  
pp. 012048
Author(s):  
N I Matskevich ◽  
V N Shlegel ◽  
A A Chernov ◽  
D A Samoshkin ◽  
S V Stankus ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Phase Transitions ◽  
Single Crystal ◽  
Weight Control ◽  
Czochralski Technique ◽  
Temperature Range ◽  
First Time ◽  
Lithium Tungstate ◽  
Dsc Calorimetry ◽  
Calorimetry Data

Abstract The heat capacity of lithium tungstate single crystal (Li2WO4) was measured for the first time in the temperature range of 319-997 K. The experiments were carried out by DSC calorimetry. The Li2WO4 single crystal was first grown by low-temperature-gradient Czochralski technique with weight control. The temperature dependence of Li2WO4 heat capacity in the temperature range 319-997 K was monotonic. According to results of our studies, there were no phase transitions in Li2WO4 in the investigated temperature range.

scholarly journals The Stress Induced Martensite-Austenite Interface in Fe-15Ni-15Cr Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 110-111
Author(s):  
G. A. Stone ◽  
G. Thomas
Keyword(s):  
Shear Stress ◽  
Slip System ◽  
Single Crystal ◽  
Single Crystals ◽  
Habit Plane ◽  
Maximum Shear Stress ◽  
Crystal Axis ◽  
Surface Study

A single crystal stressed in the [3]𝛄 direction at 185°K was transformed to 5% 𝛂 martensite and 2% Ɛ martensite by volume. The austenite slip system of maximum shear stress is the (11)𝛄 [01)𝛄. Fig. 1 shows a two surface study using the electron and optical microscopes. The a martensite is confined between £martensite plates with the (0001)Ɛ ∥ (11)𝛄. The size of the acicular martensite crystals is controlled by the spacing of the £ martensite plates. These £ martensite plates are seen in Fig. 1A as dark vertical bands. The axes of the acicular crystals lie in the (11)𝛄 plane. The £ martensite habit plane is defined as the plane perpendicular to the (11)𝛄 containing the vector defining the crystal axis.

Elastic Constants in C-plane of Single Crystal Bi 2Sr 2Ca Cu 208 between 80 K and 260 K

1990 ◽  
Vol 193 ◽  
Author(s):  
Jin Wu ◽  
Yening Wang ◽  
Yifeng Yan ◽  
Zhongxian Zhao
Keyword(s):  
Shear Modulus ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Elastic Constants ◽  
Wide Temperature Range ◽  
Sound Propagation ◽  
Anisotropic Elasticity ◽  
Ultrasonic Velocities ◽  
Temperature Range

ABSTRACTThe temperature dependence of the in-plane C11 C22. C12 and C66 modes between 80 and 260 K of superconducting crystals of Bi2Sr2Ca1Cu208 have been obtained via the measurements of ultrasonic-velocities. The anisotropic elasticity in the a-b plane of single crystal Bi2 Sr2Ca1Cu2O8 is manifest. The shear modulus of sound propagation along the [110] with the polarization has been also calculated and shows an overall trend of softening over a wide temperature range above Tc. The shear modulus C6 6 shows three obvious softening minima around 240–250 K, 150 K and 100 K.

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