The Velocity and Temperature Dependence of Rubber Friction

1954 ◽  
Vol 27 (1) ◽  
pp. 234-241
Author(s):  
A. Schallamach
Keyword(s):  
Silicon Carbide ◽  
Temperature Dependence ◽  
Tangential Stress ◽  
Exponential Function ◽  
Absolute Temperature ◽  
Rate Process ◽  
First Approximation ◽  
Rubber Friction ◽  
Reciprocal Absolute Temperature

Abstract It is shown experimentally that the velocity of frictional gliding under constant tangential stress of rubber on glass and on silicon carbide cloth is, in the first approximation, an exponential function of the reciprocal absolute temperature and of the tangential stress. It is suggested that frictional gliding of rubber is a rate process.

Basic Investigation of Tool Wear

1963 ◽  
Vol 85 (1) ◽  
pp. 33-37 ◽  
Author(s):  
H. Takeyama ◽  
R. Murata
Keyword(s):  
Tool Wear ◽  
Tool Life ◽  
Flank Wear ◽  
Cutting Temperature ◽  
Cutting Condition ◽  
Rate Process ◽  
Mechanical Abrasion ◽  
Fundamental Investigation ◽  
First Approximation ◽  
Basic Investigation

This paper treats a fundamental investigation of tool wear and tool life mainly from the viewpoint of flank wear. The result reveals that the mechanism of tool wear in turning can be classified into two basic types: The mechanical abrasion which is directly proportional to the cutting distance and independent of the temperature; and the other is, so to speak, a physicochemical type which is considered to be a rate process closely associated with the temperature, of course. Although it depends upon the cutting condition which type of wear plays a more important role, the latter is predominant under usual conditions. According to the analyses and the experimental results, it has been found out that the tool life from the standpoint of flank wear can be predicted to a first approximation by the initial cutting temperature.

Annealing and Leaching Studies With Natural and Artificial Obsidian Glass

1987 ◽  
Vol 112 ◽  
Author(s):  
T. D. MÄrk ◽  
G. Walder
Keyword(s):  
Temperature Dependence ◽  
Exponential Function ◽  
Annealing Time ◽  
Radiation Doses ◽  
Leaching Rate ◽  
Fission Tracks ◽  
Leaching Experiments ◽  
Induced Fission ◽  
Obsidian Glass ◽  
Kinetics Of

AbstractAnnealing kinetics of fission tracks (produced by induced fission of U235 in natural and artificial (doped) obsidian glass has been studied by etching microscopy as a function of annealing time and temperature. The observed annealing characteristics can be best decribed by a two term exponential function with an Arrhenius type temperature dependence of the annealing coefficients. The activation energies deduced are (0.94 ± 0.16)eV and (1.04 ± 0.15)eV for artificial obsidian and (0.83 ± O.13)eV and (0.60 ± 0.16)eV for natural (fossil) obsidian, respectively. In addition, leaching experiments of obsidian samples exposed to different radiation, doses and rates have been made at two different leachate temperatures. At a temperature of 60°C the leaching rate of irradiated samples is much larger than that of unirradiated samples, whereas at a temperature of 90°C observed leaching rates are similar.

4kV Silicon Carbide MOSFETs

2011 ◽  
Vol 679-680 ◽  
pp. 637-640 ◽  
Author(s):  
Zachary Stum ◽  
A.V. Bolotnikov ◽  
Peter A. Losee ◽  
Kevin Matocha ◽  
Steve Arthur ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Temperature Dependence ◽  
Device Design ◽  
Switching Performance ◽  
Turn On ◽  
Blocking Voltage ◽  
Vertical Mosfets

Doubly-implanted SiC vertical MOSFETs were fabricated displaying a blocking voltage of 4.2kV and a specific on-resistance of 23 mΩ-cm2, on a 4.5mm x 2.25mm device. Design variations on smaller (1.1mm x 1.1mm) devices showed on-resistance as low as 17 mΩ-cm2 with a blocking voltage of 3.3kV. Analysis is presented of the on-resistance and temperature dependence (up to 175°C), as well as switching performance. Switching tests taken at 1000V and 6A showed turn-on and turn-off transients of approximately 20-40ns.

Silicon Carbide Vertical JFET Operating at High Temperature

2008 ◽  
Vol 600-603 ◽  
pp. 1063-1066 ◽  
Author(s):  
Konstantin Vassilevski ◽  
Keith P. Hilton ◽  
Nicolas G. Wright ◽  
Michael J. Uren ◽  
A.G. Munday ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Temperature Dependence ◽  
Power Law ◽  
Current Density ◽  
Electron Mobility ◽  
Room Temperature ◽  
Protective Atmosphere ◽  
State Resistance ◽  
A Current

Trenched and implanted vertical JFETs (TI-VJFETs) with blocking voltages of 700 V were fabricated on commercial 4H-SiC epitaxial wafers. Vertical p+-n junctions were formed by aluminium implantation in sidewalls of strip-like mesa structures. Normally-on 4H-SiC TI-VJFETs had specific on-state resistance (RO-S ) of 8 mW×cm2 measured at room temperature. These devices operated reversibly at a current density of 100 A/cm2 whilst placed on a hot stage at temperature of 500 °C and without any protective atmosphere. The change of RO-S with temperature rising from 20 to 500 °C followed a power law (~ T 2.4) which is close to the temperature dependence of electron mobility in 4H-SiC.

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