Photostimulated exoelectron emission from slip lines: A new microscopy of metal deformation

1973 ◽  
Vol 44 (10) ◽  
pp. 4400-4404 ◽  
Author(s):  
William J. Baxter ◽  
Stanley R. Rouze
Keyword(s):  
Exoelectron Emission ◽  
Slip Lines ◽  
Metal Deformation

Photostimulated Exoelectron Emission from Slip Lines—A New Microscopy of Metal Deformation

1973 ◽  
Vol 31 ◽  
pp. 140-141
Author(s):  
William J. Baxter ◽  
Stanley R. Rouze
Keyword(s):  
Tensile Deformation ◽  
Exoelectron Emission ◽  
Photoelectron Emission ◽  
Electron Multiplier ◽  
Slip Lines ◽  
Fluorescent Screen ◽  
Image Intensification ◽  
Metal Deformation ◽  
Photoemission Electron

Plastic deformation of metals enhances photoelectron emission, an effect known as photostimulated exoelectron emission. It has been proposed that the electrons are emitted from microcracks produced in the oxide. We have observed this phenomenon directly in a photoemission electron microscope (PEM) and shown conclusively that such emission does indeed originate from cracks in the oxide at slip lines.The PEM consists essentially of two magnetic and one electrostatic immersion lens. The sample is illuminated with ultraviolet radiation, and the photoemitted electrons are imaged on a fluorescent screen. A Channeltron Electron Multiplier Array provides image intensification. The sample is deformed in situ by bending to produce tensile deformation of the surface under study.

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

scholarly journals Slip lines in front of a round notch tip in a pressure-sensitive material

1994 ◽  
Vol 19 (1) ◽  
pp. 29-38 ◽  
Author(s):  
H.-Y. Jeong ◽  
X.-W. Li ◽  
A.F. Yee ◽  
J. Pan
Keyword(s):  
Sensitive Material ◽  
Slip Lines ◽  
Pressure Sensitive ◽  
Notch Tip

Thermally Stimulated Luminescence and Exoelectron Emission Mechanism of the 430 K (D') Dosimetric Peak of a-Al2O3

1999 ◽  
Vol 84 (1) ◽  
pp. 253-256 ◽  
Author(s):  
G. Moln r ◽  
E. Papin ◽  
P. Grosseau ◽  
B. Guilhot ◽  
J. Borossay ◽  
...  
Keyword(s):  
Exoelectron Emission ◽  
Emission Mechanism ◽  
Thermally Stimulated Luminescence ◽  
Dosimetric Peak

CORRELATION BETWEEN ELECTRIC CHARGING OF THE SAMPLE SURFACE AND KINETICS OF OPTICALLY STIMULATED EXOELECTRON EMISSION (OSEE) FROM CRYOSOLIDIFIED NaCl SOLUTION

1990 ◽  
Vol 04 (03) ◽  
pp. 201-209
Author(s):  
A. GIEROSZYŃSKI
Keyword(s):  
Electric Fields ◽  
Surface Potential ◽  
Surface Region ◽  
Sample Surface ◽  
Exoelectron Emission ◽  
Nacl Solution ◽  
Emitter Surface ◽  
Emitter Layer ◽  
The Relationship ◽  
Kinetics Of

It was found that OSEE kinetics from electron bombarded cryosolidified NaCl solution, depend on electric charging of the sample surface. It was shown that from the relationship between the maximum surface potential and the parameters of OSEE kinetic, intensities of electric fields in the emitter layer could be estimated. It is supposed that nonhomogeneous electric fields existing in the emitter surface region, influence the emission levels responsible for the course of OSEE kinetics.

Sign in / Sign up

Export Citation Format

Share Document