The detection of fatigue damage by exoelectron emission

Abstract

Plastic deformation of metal enhances the photoelectron emission producing so-called exoelectrons In our experiments the metal surface is scanned by a small spot of ultraviolet light and the electron emission is recorded as a function of position of the light spot. Results for aluminum and steel demonstrate that fatigue deformation produces exoelectron emission after less than 1% of the fatigue life. The regions of emission are very localized; some are beyond the resolution of the apparatus (15 μm). The localized emission increases throughout the fatigue life, and failure finally occurs in the region of most intense emission. The regions of intense emission are attributed to the development and propagation of fatigue cracks.

Method for the analysis of nonselective spectra of optically stimulated electron emission from irradiated dielectrics

“…Determine parameters S •• and τ of the obtained kinetic curve I(t) using Eqs. (14) and (16), respectively.…”

“…The method of optically stimulated electron emission (OSEE) [12,13] is used increasingly in studies of photosensitive defects and properties of the surface layer of materials. The theory and hardware of the OSEE method have been well developed and it has shown itself useful in studies of fatigue failures and plastic deformations in metals [11,14], color centers in surface layers of oxide crystals, and glasses [15]. However, some methodological difficulties limit the development and wider use of OSEE in studies of point defects on the surface of dielectric materials.…”

“Observation” of dislocation motion in single crystal and polycrystalline aluminum during uniaxial deformation using photoemission technique

“…Photostimulated electron emission has been employed to monitor surface oxide fracture [6] and slip band formation during fatigue and deformation [7][8][9][10]. For instance, Baxter reported a linear increase of PSE with strain at strains less than 0.10 in aluminum and copper.…”

Determination of strain localization in aluminum alloys using laser-induced photoelectron emission

“…17,18,[28][29][30][31][32][33][34][35][36][37][38][39][40] Electron microscopy, autoradiographic stripping, 29 and photoemission spectroscopy 17,37 showed that these signals were closely associated with the formation of slip lines and bands on deformed surfaces. 17,18,[28][29][30][31][32][33][34][35][36][37][38][39][40] Electron microscopy, autoradiographic stripping, 29 and photoemission spectroscopy 17,37 showed that these signals were closely associated with the formation of slip lines and bands on deformed surfaces.…”