Determination of Strain Localization in Aluminum Alloys Using Laser-Induced Photoelectron Emission.
M Cai, S C. Langford, Lyle E. Levine, J T. Dickinson
Uniaxial tensile deformation of oxidized aluminum produces low work-function patches of fresh metal that can be probed by measurements of photoelectron emission during exposure to ultraviolet light. Strain localization alters the distribution of fresh surface metal produced by subsequent deformation. We report measurements of photoelectron emission during uniaxial testing of polycrystalline Al (1200), Al-Mn (3003), Al-Mg (5052), and Al-Mg-Si (6061) alloys where the broad face of the gauge section is exposed to pulsed excimer laser radiation (248-nm). The growth rate of photoelectron intensities during testing shows a discontinuity which we attribute to the transition from more homogenous deformation before localization to the principally localized deformation associated with shear bands. This increases the rate of fresh metal production along the narrow (not illuminated) surface of the gauge section relative to the broad surface (illuminated). In all four materials, the strain at the discontinuity is somewhat below the strain given by the Considere criterion, consistent with the role of microstructural effects in strain localization. We expect that information provided by photoelectron measurements can significantly improve quantitative models of strain localization.
, Langford, S.
, Levine, L.
and Dickinson, J.
Determination of Strain Localization in Aluminum Alloys Using Laser-Induced Photoelectron Emission., Journal of Applied Physics
(Accessed December 9, 2023)